HOLLYWOOD -- The gray-on-gray waiting room for "The Arsenio Hall Show" was icily elegant: wraparound sofas; a glossy wet bar; artful cantaloupe slices that former "Diff'rent Strokes" ingenue Dana Plato scarfed after confiding to 4 million viewers how special it was, sitting gap-legged and panty-free in a recent Playboy. Then everybody saw the mouse. It sat, completely ignoring the photographer who leaped onto an ottoman, the reporter who dived for a table. Leisurely, as if it had every right to hang out among the semi-famous, the ultra-hip, the mouse glanced left, then right. It sniffed an open case of Soave wine and vanished. Hall harrumphed in triumph. "I told you there was a mouse in this joint," he announced to his publicist. "Two weeks ago I saw it, but did you believe me when I told you? "Nobody around here takes me seriously." Believe that, you probably swallow the fascinated way Hall leans forward, elbows on his Armanied kneecaps, when celebs chatter about life in the fame lane. Because Hall has the best -- and in this town, perhaps the only -- guarantee for getting taken very, very seriously: a hit. The Nielsens show that Hall's six-month-old self-proclaimed "talk show for the MTV crowd" has strutted past David Letterman's and Pat Sajak's talkfests and is inching up on Johnny the Great's (three weeks ago Hall's show whipped Johnny's for the first time in New York). Stars like Anita Baker, Tony Danza and Farrah Fawcett call him to be on his show. Supermarket tabloids won't leave him alone ("ARSENIO PURSUES ROBIN GIVENS! ROARS IRON MIKE: 'I'LL KILL HIM!' "). Hall is hot. He just finished filming a role in "Harlem Nights," best pal Eddie Murphy's directorial debut costarring Redd Foxx, Richard Pryor and Murphy, and set for a Christmas release. Last month he started cutting an album for MCA as "Chunky A" (short for Chunkton Arthur Hall), his own humongous long-lost half-brother. (Hall wore a "fat suit" to introduce Chunky and his theme phrase -- "Chunky A is love, the overweight DJ sent from above" -- on a recent show.) Hall's so hot that he says he doesn't have time to worry about being sued for $10 million by Willis Edwards, head of the Beverly Hills-Hollywood NAACP, who claims that Hall defamed him last January by calling him an "extortionist" in a story in the Los Angeles Sentinel -- an allegation Hall denies. Edwards last year accused Hall of not having enough black producers, directors or writers on the show's staff; Hall says that at least 30 percent of those staff positions are filled by blacks. But that suit might help explain why Hall has largely traded his habit of trashing friends, foes and himself in interviews for the rudiments of a protective cover. "Why won't you tell me who you're seeing?" begs a reporter accustomed to the old Hall, who'd provided everything from insights on his sexual escapades to his mom's phone number. "Because you're trying to play me out in a national {publication} and I've got to watch myself," he responds. These days, he has no intention of letting you know how worried he is, how angry. He'd rather you be taken in by that "see-all-my-gums?" grin; the schoolboy charm that allows him to get away with asking Brooke Shields if she's still a virgin and playing such flagrant on-air footsie with actress Emma Samms that everybody watching knew they'd had an affair. But no matter how popular or charming he is, how distractingly naughty, one thing is clear: Hall knows that to some of his critics, he's like the waiting-room mouse -- an undisputed attention-grabber who slipped into the wrong neighborhood. And it drives him crazy. "This is my place," he says. "I invite people to my place, not necessarily to do an interview -- I'm not a journalist -- but to have conversations. I supply the keyhole for America to peep through and see their favorites talking." Hall's problem is that nobody as def as he is has ever supplied the keyhole. Proof: The star actually uses the term -- which in street vernacular connotes cool, great, the ultimate -- on the show. ("For those of you who are confused," he explained once after bandying the term with actor-hoofer Gregory Hines, "we are not referring to the hearing-impaired.") And some audiences and critics -- older, often white, decidedly un-def -- don't get it. Some have complained that the show's frankly black sensibility -- Hall consistently features African American celebs and music acts, and is more likely to joke about James Brown and Whitney Houston than about Dan Quayle or Ollie North -- excludes them. They say that watching Hall's show is a bit like hanging out at a party to which they weren't invited, one where they're the least hip people in the room. Implicit in such complaints, says Hall, his voice going Dirty Harry soft, is the assumption that it's fine for shows like Carson's or Letterman's to consistently feature a white sensibility, and that it's okay for blacks, Hispanics and other minorities to do the adjusting. "That mentality keeps television from expanding to higher levels, and expanding to other people," he says. Because white people who feel that way, he says, obviously can't imagine "what it's been like for us for all these years." He wishes his critics would "sit down for a minute and try to understand my show as a huge amount of white America is doing, like I did when I watched my first Bob Hope special, my first 'Three Stooges.' ... My whole culturization requires that I understand everything that America is." The voice moves faster, fiercer now, barely scaling a whisper. "My show," he continues, "is not a black show, it's not a show to take over the airwaves, it's a show to say, 'Let's share the medium now.' ... Beaver's dead, baby. Beaver's gone. And it's time to let some blacks move into that neighborhood." To drive the point home, Hall, who often searches pop culture for a witness, finds one in the lyrics to a song popularized by four fairly def white boys: "I am black, offering a theory," he says. "Let's come together, right now, over me." Now, even true believers may have some reservations about Hall's late-night love-in, syndicated six days weekly on 160 stations nationwide (that's 95 percent of U.S. markets), including Channel 20 locally, by Paramount Domestic Television, in association with Arsenio Hall Communications Ltd. Some decry his fidget-inducing penchant for over-complimenting guests; others feel his outrageousness occasionally backfires (guest Jesse Jackson's first reaction to Hall's gift of a bucket of chicken was to recoil, though he kept hope alive by munching his way through the appearance). Others wonder about the open-lap policy that encourages actresses like Mary Frann, Sally Kirkland and "Falcon Crest's" Ana Alicia to ogle, sit on or otherwise woman-handle the acquiescent Hall. But to fans, none of this does much damage. Because even when Hall's at his naughtiest -- cranking his arm and barking his trademark nasty-dog bark (his studio audience, TV's noisiest, also yaps, howls and cranks its approval), or explaining to females why their boyfriends are unfazed by skepticism about LaToya Jackson's cleavage ("men don't care if she bought them"), he manages to seem, well, mischievous. Like the preschooler who suggests to your Great-Aunt Ida that she pass on the lemonade because "Mommy says you drink too much." Hall's willingness to make mistakes, to be open enough to let audiences peep through the keyhole, could be his biggest weakness. It's also his greatest strength. The resulting lack of pretense, of defenses, ultimately puts guests -- and many viewers -- on his side. "He's like a little kid who's about to get into some devilment," says fan La Rhonda Whitehead, a Detroit singer who was among several stars of the stage show "Don't Get God Started," who met Hall recently in Los Angeles. "Like, you can't get mad at him, you know?" Who could get mad at a guy who, in an effort not to ego-trip ("I'm saving the clippings and tapes so I can trip later"), devised a plan to help kids stay away from drugs? "Right now I've got the ear of America's 18- to 34-year-olds, so ... when I'm not doing the show, I'm trying to figure out what else I can do to help. That's how I came up with my whole drug campaign." With Paramount's help, Hall filmed a series of stark black-and-white commercials in which he talks with young addicts about the horrors of drug addiction. Currently, the spots are airing on MTV, VH-1 and various independent stations across the country. How could anybody not love a guy who refuses to go bowling with Mr. Box Office himself, Eddie Murphy? ("He calls me all the time with, 'Let's go bowling,' and I say, 'Yo, man, bowling's bull -- when you're ready to not bowl, we can hook up.' ") A guy who admits, "I could easily get caught up in gold chains, fur coats in the summer, sitting in a nightclub saying, 'Bring me another sloe gin fizz and tell that 'ho over there I'd like to meet her.' But my mom used to say, 'Idle mind, workshop of the Devil.' So I stay busy." Like, is it possible not to be captivated by a fellow who, as a Christmas present last year, moved mom Annie Hall from Cleveland to her very own Los Angeles condo? Who insists on taking out his own garbage and parking his own car? Well, sure. Because just often enough, Hall's likableness and sense of purpose are tempered by a hair-singeing display of ego. Like when he asserts, "I don't believe you can look in the archives of talk show hosts and find a guy who does it as well as I've done it in less than a hundred shows," or "When I look at the other talk show hosts around, there are no comic geniuses there; they don't do as many things as I do." Hall is a born chameleon, just like the Cleveland kid who distanced himself from the neighborhood children but spent hours practicing magic tricks so he could wow them at self-promoted magic shows. This was a kid Annie Hall had to beg to "go play, get on a baseball team, get your ass out of the house and do something," he recalls. The only child of a Baptist preacher who died a decade ago, Hall was raised by his divorced mother, grandmother and godmother. From the beginning he was a loner who spent most of his time at home, doing magic, listening to the Temptations and the Miracles while trying to copy their steps, and writing newspapers that nobody read. And he was obsessed with talk shows. His mother has said that the pre-adolescent Hall used to watch Johnny Carson and announce, "I want to do what he's doing." Even Hall's show logo -- an illegibly scrawled Arsenio -- is the result of hours spent in study hall copying the way Dinah Shore signed her name on her show. "I knew I was going to use it someday," he says now. There wasn't much demand for the autograph when Hall, just graduated from Kent State University, signed on as a salesman with the Detroit company that makes Noxzema skin cream. Perhaps he was taking his cue from the college drama counselor who'd sniffed, "There are audiences and there are stars. You were meant to be in the audience." Still, he started his comedy career in Detroit, refined it in Chicago and eventually took it to L.A. If there was one turning point in Hall's early career, it was the moment three years ago when singer Patti LaBelle, for whom he was opening, advised the young comic to ignore the "experts" who'd told him he was too "ethnic," too "up" and too "physical" and just to be himself. And who, exactly, is that? Hall laughs, adjusting his customary off-the-air baseball cap. "If I tell you who I am, my publicist will go crazy, but I'll tell you anyway," he says. "I am an entertainer who was given many talents in many areas so I could do what I'm doing better than anybody's ever done it before. ... I feel I was born to do it." Okay. But as soon you're ready to paste the scarlet "E" on that high forehead, Hall lets loose with an almost breathtaking -- by Hollywood standards -- bit of humility; a bit that reveals his ongoing connection with his preacher father. "At times I've wondered, 'Why me?' Because there are people who are more talented, who are nicer, who need it more, who have worked harder than me. Why me? Then it dawned on me. It's what He wants. ... My thought is that I'm supposed to do something with it that maybe someone else wouldn't." What Hall did with it the night of the LaBelle show was to cut loose with his own brand of cocky-humble-innocent-bawdy badness. And he got his first standing ovation for doing it. His break into prime time was engineered by Joan Rivers, who felt Hall's insouciant, no-holds-barred style was a good match for her own. One night when she was guest-hosting for Johnny Carson, presidential daughter Patti Davis canceled her appearance and Rivers subbed Arsenio, despite Carson's lukewarm feelings about the comedian. When Rivers was fired from her own much-hyped Fox Broadcasting talk show, "The Late Show," Arsenio filled in for her, surprising everybody with a show that was loose, unpredictable -- on one show, he challenged Elliott Gould to a game of one-on-one basketball, soundly spanking him -- and, yes, def. Murphy and Paramount lured Hall away from Fox with a movie contract and an offer to costar in "Coming to America." By the time the studio approached him about launching his own show last year, he knew exactly what position he required -- executive producer and star (that way, he says, "If I fail, it will be the way Arsenio chose to fail. And I'll be happy through it all"). He also knew precisely who he wanted in his audience: MTV fans. "These kids didn't have a talk show. Where do they see Duran Duran when they want to hear them talk? Where does the urban contemporary audience see Bobby Brown, the number one pop -- not R&B, but pop, that means white people bought it -- crossover artist in America, who could not get on a talk show?" Not that the be-bop crowd is the only one tuning in. Hall gets letters from grandmothers who thank him for introducing them to Tiffany and Lisa Lisa and Cult Jam; from 6-year-olds miffed that their moms won't let them stay up to watch. And sacks of them from adoring women who say ... Women. These days, they're not Hall's favorite interview subject. Because despite the show's rampant lap-hopping, despite the rumors that have paired him with everyone from Brooke Shields to Whitney Houston to Marlee Matlin (we won't even deal with Hall's favorite, which had him in a love triangle with Mike Tyson and Murphy), despite the eager groupies who've seemingly made a career of hopping from him to Michael Jordan to Murphy to Tommy Hearns, Hall has only one true love -- his show. How committed to the show is he? So committed, he jokes, that if "A Different World's" Jasmine Guy -- of the taut dancer's body and witchy siren's face, who holds a lifetime spot on Hall's World Class Def list -- yanked him by his 100 percent cotton collar and growled, "Marry me," he'd gasp, "No." So he worries about loneliness. More specifically, he worries about not being worried about loneliness. He should be shaken, he thinks, by the fact that on most nights -- after he wraps the show, hops into his black 1988 Mustang and drives home to his West Hollywood condo -- the only voices that greet him are Oprah's and Phil's, daily recorded on his VCR. Is it normal, he wonders, to enjoy being alone so much? Is it smart to reject the joys of a wife and a family in lieu of, like, a TV show? "It's one of my most agonizing thoughts," says Hall. "I'm 30 {actually, boyhood acquaintances put him closer to 34}, but I guess I can always hook up with a young girl -- the time factor isn't as much a consideration for men as it is for women. "But I don't see any end in sight," he continues. "I wish I wasn't so into what I'm doing. Because you have to have a balance. Some people can do it, have careers and families. They want to do the family thing. And it scares me that I haven't had that desire." His voice gets softer, more urgent. "Is it going to be too late when I decide? Do I want to do it and I'm too stupid and obsessed with my career? I'm totally scared about my future and when it's all going to happen." It could have happened, he says, with gorgeous singer-choreographer Paula Abdul, who hung out with Hall for several months last year. "She is -- something else," he begins. Suddenly, he's totally tongue-tied. "She's what, she's -- I consider her -- she's, she's really, she's -- the perfect woman," he stammers. For once, his innocence seems pure, uncut by ego or raunchiness. "Ye-eahh. But she has a career and I have a career and those are, well, relationship-busters. ... I am literally so obsessed with my career that {there's} a terrible sickness to it. ... Plus I'm a real loner. I couldn't imagine living with somebody. I spend most of my time by myself, alone. That scares me." Hall worries about being wanted for himself. And there's only one person -- outside of his mom, his producer and a few female buddies -- whose motives in that regard are above suspicion. That person just happens to be, as Hall can't remind you often enough, "the number one box office draw in the world." "Having Eddie Murphy as a best friend is hard," says Hall. "I talked to a reporter the other day who said, 'What do you say about the criticism that you name-drop Eddie Murphy's name?' I said, 'Have you ever mentioned your brother's name in conversation?' He's my brother. The closest man in the world, probably, to me." Hall says Murphy's fame isn't the appeal. "He's this sensitive, caring, generous, kind person, much more so than myself. If you have an opportunity to walk away from one of us and do battle with the other, walk away from me and do battle with him. Because Eddie will turn the cheek, forgive you afterward. "Me? I will be outside your house, as soon as the arm heals, yelling, 'Come on, mother.' " Ask Hall to name another close friend who can give some real insight about him and he shifts in his chair, clears his throat and can't name a soul. Hall shakes his head slowly. "You don't know how much I would like to give you a name, somebody who is close," he says finally. The reason he can't? "I don't trust people," he says. "I don't trust people. When I first met Eddie, that was the thing about us -- nobody was using anybody. ... I've seen Eddie lose friends because people are hanging around him because they want something. It's a real problem, what people want." So what does Hall want? More respect, probably. A larger, more diverse audience. The total trust of his white, un-hip bosses at Paramount. A mandate to continue his mission -- bringing us together, in our respective late-night living rooms, over him. "The wheels for education and change, they grind slowly," he says, staring at his high-top Reeboks, his favorite brand because the Reeboks Corp. has no involvement in South Africa. "Getting in here was important. And now there are things I have to do now I'm in. ... When I told them I wanted {black rap singer} Tone Loc, some people here refused to put his name in my advertisements. And I said, 'You either put his name in there or you get yourself another host. Just because you don't know how important he is, you won't put him in? You put Lloyd Bridges in.' " He looks up. He flashes the grin. The bad-boy smile and the angry-man words don't jibe but, Arsenio-like, he gets away with it. "This is my show and it's my sensibility," he says. "I'm the engine in this car. And if it's not running the way they wanted it to run, they should have gotten themselves another engine."