Celebrities glitter all over the dial this week: they celebrate the 75th birthday for show-biz mecca Las Vegas and the 40th birthday for Howdy Doody, honor Joan Collins in a "roast" and applaud those entertainers named to the Television Academy Hall of Fame. Look for the first of two presidential candidates' debates from the Kennedy Center, Hallmark Hall of Fame's lavish production of "Secret Garden," television movies starring David and Meredith Baxter Birney, Tom Bosley and Carol Burnett, the Clio Awards (for commercials), a wedding on "Dallas" and the 200th episode of "Knots Landing."

SUNDAY REDSKINS VS. NEW YORK GIANTS at 4 on CBS

LAS VEGAS' ANNIVERSARY at 9 on ABC

THE LONG JOURNEY HOME at 9 on CBS

ROYAL VARIETY PERFORMANCE at 10 on 26 Afternoon fare: Vice President George Bush appears on Marvin Kalb's live interview series with presidential candidates on WETA, then the football fans get the remote control for the Redskins-New York Giants game at 4. At night, stars who made it big in Las Vegas gather for a two-hour "All-Star 75th Anniversary" tribute to that entertainment mecca (9 on ABC). Frank Sinatra and Sammy Davis Jr. sing "The Way We Were" and Ray Charles does the finale. Also aboard are Dean Martin, Jerry Lewis, Englebert Humperdinck, Don Rickles, Tom Jones, Wayne Newton, Pia Zadora, Nell Carter and the McGuire Sisters, plus Debbie Allen and Mary Hart. Also at 9, David Birney and Meredith Baxter Birney show up in CBS' "The Long Journey Home," the story of a Vietnam vet presumed missing in action whose unexpected return plays havoc with his wealthy wife's plans to remarry. But it isn't a Vietnam drama to pull at your heartstrings -- instead, it's a melodrama that takes the pair globetrotting as they try to shake an assassin. NBC offers a previously postponed episode of "Night Court" and follows with new "Beverly Hills Buntz." At 10, Gene Kelly hosts a two-hour special devoted to dancing that was performed before Queen Elizabeth. On the card: The cast of "Dancin'," Tommy Tune and Twiggy doing numbers from their Broadway hit "My One and Only," and Natalie Makarova and Anthony Dowll performing a pas de deux. Guests: O.J. Simpson, Lindsay Wagner and Moon Zappa as Murphy the Female Biker on "Student Exchange" (7 on ABC); Dorothy Lamour and Geoffrey Lewis on "Murder, She Wrote" (8 on CBS); Howard Duff on "Werewolf" (8 on 5 and 45); Dick Butkus on "My Two Dads" (8:30 on NBC); Steve Martin on "The Tracey Ullman Show" (9 on 5 and 45). MOVIES: It's Humphrey Bogart Day on WDCA, starting at noon.

MONDAY CBS THIS MORNING at 7:30 a.m.

TELEVISION HALL OF FAME at 8 on 5

THE NUTCRACKER at 8 on 26

FATAL CONFESSION at 9 on NBC

HALLMARK: SECRET GARDEN at 9 on CBS

WILTON NORTH REPORT at 11:30 on 5 and 45 Kathleen Sullivan and Harry Smith take over the reins of new "CBS This Morning," replacing Mariette Hartley and crew on the old "Morning Program." Hallmark Hall of Fame can be counted on for television productions of fine quality, so don't overlook "The Secret Garden" just because it's based on a children's book. American actress Gennie James ("Places in the Heart," "Alex: The Life of a Child") stars as orphan Mary Lennox, who is sent to rural England to stay at imposing Misselthwaite Manor. Initially lonely and disagreeable, Mary finds a long-abandoned, magical garden that changes her outlook. She in turn manages to change the lives of two self-centered lads, Dickon Sowerby (Barret Oliver), a boy of the Yorkshire moors who plays the flute, and the hypochondriacal invalid Colin Craven (Jadrien Steele), son of the estate's owner. Three acclaimed British actors, Derek Jacobi, Billie Whitelaw and Sir Michael Hordern, play Archibald Craven, lord of the manor; housekeeper Mrs. Medlock, and crusty old gardener Ben Weatherstaff. Lucy Gutteridge plays Mrs. Lennox, Colin Firth is the adult Colin and Julian Glover plays Col. McGraw. Frances Hodgson Burnett's 1911 story, filmed at Highclere Castle at Newbery, is the 154th Hallmark Hall of Fame offering.

Other choices include the American Ballet Theatre production of "The Nutcracker" (8 on 26) featuring Gelsey Kirkland as Clara, Alexander Minz as Herr Drosselmeyer and Mikhail Baryshnikov in the title role. Fox stations carry the two-hour "Television Academy Hall of Fame Show" at 8, presenting the fourth annual awards to Johnny Carson, Jacques Cousteau, Jim Henson, Bob Hope, network executive Leonard Goldenson, Eric Severeid and the late Ernie Kovacs (Edie Adams will accept). The show, with taped vignettes and testimonials by other celebrities, took place Nov. 15 in Los Angeles. Tom Bosley leaves his Glad bags behind tonight to play a parish priest with a knack for solving mysteries. Bosley is Father Dowling, who believes that the apparent suicide of a young millionaire (Kevin Crowley) is really a murder. Tracy Nelson plays a young nun, Leslie Nielsen a powerful senator, Sada Thompson the widow of an oganized-crime leader. Peter Scolari, Mary Wickes and Susan Blakely costar. And at 11:30, Fox stations introduce "Wilton North Report," an offbeat look at the day's events with anchors Phil Cowan and Paul Robins, plus Morton Dean, Nancy Collins, Greg Jackson, Jack LaLanne and Tama Janowitz. Guests: Burt Reynolds, Tim Hutton, Mel Gibson and host Chuck Norris on "Ultimate Stuntman" (8 on ABC). MOVIES: "Norma Rae" (8 on 20). SPORTS: Raiders at Seattle (9 on ABC).

TUESDAY 1987 CLIO AWARDS at 8 on 5

CANDIDATES DEBATE at 9 on NBC

ORIGINS at 10 on 26 Jill Eikenberry and Michael Tucker host the first telecast of the Clio Awards for the best television commercials in the world (8 on 5). The hour-long show will feature some top commercials of the past, such as the "Speedy Alka-Seltzer" spot from 1953, Clara Peller's "Where's the beef?" ad for Wendy's, and the California Raisins' song-and-dance pitch. Also at 8 is WHMM's documentary on Seventh and T streets, hosted by singer Mary Jefferson. At 9, NBC carries the first of two debates among presidential candidates from the Kennedy Center. Stepping up during the two-hour session are Republicans Bush, DuPont, Dole, Haig, Kemp and Robertson and Democrats Babbitt, Dukakis, Gephardt, Gore, Jackson and Simon. Tom Brokaw moderates. Also at 9, WTTG begins "The Infinite Voyage," a 12-part series that aired on PBS stations, and ABC's "Moonlighting" finds David in jail while the gang at the Blue Moon celebrates the birth of Maddie's baby. Christopher Reeve hosts a two-hour special called "Origins" (10 on 26) narrated by William Conrad. The program, filmed on five continents, tells the story of the beginning of the universe, the Earth, life and human intelligence. Guests: ALF, Jason Bateman, Corbin Bernsen, Rhea Perlman, Malcolm-Jamal Warner, Betty White and Granville Van Dusen on "Matlock" (8 on NBC); and Millicent Collinsworth as herself, a blind woman who is the witness to a the murder of a cop, in "Houston Knights" (8 on CBS). Collinsworth made headlines in Los Angeles when she was assaulted and received no help from passersby.

WEDNESDAY SEASONAL DIFFERENCES at 4 on 13

ALL-STAR PARTY FOR JOAN COLLINS at 9 on CBS At 4, ABC's Afterschool Special carries "Seasonal Differences," the story of upheaval caused when a nativity scene is placed on the school lawn. Megan Follows, Ute Hagen and Melba Moore star. WJLA will air the show on Friday. At 8, flutist James Galway is joined by the Royal Philharmonic Orchestra, the Ambrosian Singers of London and the Boy Choristers of St. Alban's Abbey in Hertfordshire, England, for an hour-long Christmas holiday special. At 9, CBS carries a "roast" for actress Joan Collins with Clint Eastwood, James Stewart, Lynn Redgrave, Robin Leach, Bea Arthur and others. It's over in time to watch her on ABC's "Dynasty." SPORTS: Bullets vs. Indiana Pacers (7:30 on 20). MOVIES: "Amadeus" (7 on 5, 8 on 45); "Twelve Angry Men" (midnight on 20).

THURSDAY SIMON & SIMON at 9 on CBS

PLAZA SUITE at 9 on ABC

KNOTS LANDING at 10 on CBS CBS rebroadcasts "The Life and Adventures of Santa Claus," telling the tale of Santa from boyhood onward in a musical presentation based on a story by L. Frank Baum, author of "The Wizard of Oz." Then "Simon & Simon" returns to the network lineup. On NBC, Denise Huxtable joins the Hillman track team ("A Different World" at 8:30) and Judge Harry Stone faces a man who plans to destroy the original United States Constitution ("Night Court" at 9:30). Carol Burnett shows up in a new version of Neil Simon's "Plaza Suite," a trio of vignettes all set in New York's Plaza Hotel. In the 1971 movie, Walter Matthau appeared in all three tales with three actresses. Burnett pairs up with Richard Crenna as parents of the bride (Erin Hamilton, Burnett's daughter), with Dabney Coleman as a former boyfriend who is now a Hollywood producer, and with Hal Holbrook as a couple with a shaky marriage. The 200th episode of "Knots Landing" finds the community mourning Laura's death. Original series regular John Pleshette returns as Richard Avery, Laura's first husband. Guests: Betsy Palmer on "Out of This World" (7:30 on 4); Tom Skerritt on "Cheers" (9 on NBC). MOVIES: "In the Heat of the Night" (noon on 20).

FRIDAY HOWDY DOODY'S 40TH BIRTHDAY at 8 on 5

DALLAS at 9 on CBS It's Howdy Doody time on WTTG in a two-hour special recapturing the Doodyville characters and their leader, Buffalo Bob Smith, who appeared for 13 years on television. "Howdy Doody," which premiered in December 1947, featured Clarabell, a seltzer-squirting clown; Chief Thunderthud whose greeting was "kowabunga"; and Princess Summer/Fall/Winter/Spring. Celebrity guests offer 40th-birthday greetings. NBC competes with "Mickey's Christmas Carol" at 8, ABC reprises the opener for "I Married Dora" and CBS sticks with its unusual "Beauty and the Beast." On "Dallas," Ray and Jenna exchange wedding vows with Bobby Ewing as best man. Guests: John Saxon and Maggie Cooper on "Falcon Crest" (10 on CBS). MOVIES: "His Girl Friday" (4 on 53); "The Entertainer" (8 on 54).

SATURDAY JAMES STEWART: IT'S A WONDERFUL LIFE at 8 on 26 WETA, closing its pledge drive tonight, checks in with a tribute to James Stewart and one of his most enduring films, "It's a Wonderful Life." Johnny Carson hosts the retrospective of Stewart's life and career, with clips from his movies and interviews with friends, including President and Mrs. Reagan. Donna Reed and Lionel Barrymore star with Stewart in the 1946 Frank Capra classic, the story of a man on the brink of suicide because he thinks his life has been a failure. SPORTS: Football: Army vs. Navy from Philadelphia (2 on CBS). Basketball: Indiana vs. Kentucky (2 on ABC); Notre Dame vs. Louisville (4:30 on ABC); Loyola vs. Towson (8 on 11). Also: Heisman Award (5:30 on CBS). CABLE NOTES C-SPAN Sunday, candidates for the Republican presidential nomination address the GOP Governors Association meeting in Santa Fe, N.M.; Thursday, former Federal Reserve Board chairman Paul Volcker delivers a luncheon address during the American Enterprise Institute's 11th annual policy conference. HOME TEAM SPORTS

Tuesday, Capitals vs. Edmonton Oilers at 7:30; Thursday, Bullets vs. Atlanta Hawks at 7:30; Friday, Capitals vs. New York Islanders at 8; Saturday, Virginia Military Institute at Georgetown at 2, Bullets vs. Seattle Supersonics at 7:30. USA

USA's six-hour Thanks-for-Giving special for the Juvenile Diabetes Foundation begins at 7 on Sunday, with hosts Michael Landon and Gloria Loring. Mary Tyler Moore is international chairman of the foundation. This marks the first fund-raising special for USA. NICKELODEON

Viewers of "Nick at Nite" wrote in to explain why their lives were like sit-coms, so the show's writers turned them into ... five-minute sit-coms, taped at the winners' homes and offices. Friday, comedian Roseanne Barr hosts the offerings. A panel of entertainment industry professionals will select the best. TBS

Saturday, TBS will carry the controversial documentary that PBS refused to air last year: "Television's Vietnam: The Impact of Media," produced by the conservative Accuracy in Media group. Charlton Heston narrates; a 3-minute panel discussion follows.