Television will provide a mantra for the '90s. Already, contenders have emerged:

"The bitch set me up." -- Washington Mayor Marion Barry, in the infamous FBI undercover videotape.

"Don't have a cow, man." -- Bart Simpson, hero to millions.

"I've fallen, and I can't get up." -- Prostrate granny in a commercial for a medical emergency gizmo.

On television as in other areas of American life, 1990 was marked by myriad embarrassments, lowered expectations and flagrantly unseemly behavior -- Roseanne Barr mangling the national anthem prior to a San Diego Padres game; Delta Burke trundling from talk show to talk show to complain of alleged mistreatment on the set of her sitcom "Designing Women"; and Arsenio Hall, late in the year, going berserk as he lambasted a homosexual who stood up in the audience to protest Hall's anti-gay jokes.

In addition to these imbroglios, a huge fuss erupted in May when scatological comic Andrew "Dice" Clay was booked as a guest host of "Saturday Night Live." Cast member Nora Dunn boycotted, as did chrome-domed songstress Sinead O'Connor. Clay's actual appearance seemed anticlimactic after all the self-righteous hullabaloo. A subsequent feature film, "The Adventures of Ford Fairlane," bombed and a Clay-in-concert movie was shelved.

Should one be cheered that Clay was so soundly trounced? It's hard to be when the anti-Clay campaign reached such a ferocious fever pitch. He was to be stoned and garroted, it appeared, for the crime of insensitivity. People for the American Way, a civil liberties group, called 1990 the Year of the Censor for all the attacks made on free expression; nobody seemed to want to defend comic Clay's right to it.

Perhaps the general spread of rudeness and bad form can be traced to the unsavory example set by marauding Iraqi dictator Saddam Hussein, a grimly persistent presence who followed his invasion of Kuwait with a series of bizarre TV specials. In one he patted a 10-year-old hostage's head and pretended to be genial Uncle Crackpot. In another, he proposed yet more air time for himself, via a globally televised debate with George Bush and Margaret Thatcher.

Saddam, reportedly a loyal viewer of CNN, was apparently trying to turn international terrorism into a media event. It was Dan Rather of CBS News, meanwhile, who snagged the first interview with Saddam since the crisis began, but Rather's reward for his efforts included more crabby bad-mouthing back home by former anchor Walter Cronkite, miffed that CBS failed to hold a party on the occasion of his 40th anniversary with the network.

Have a party? Good grief, CBS was busy just trying to hold its head above water, as the network logged its worst year ever, cursed by poorly performing shows and huge sports contracts that went sour. CBS will report losses for the fourth quarter of 1990 and some network executives expect it to lose money in 1991.

Elsewhere on American television, all the networks, poor old things, sang the blues, scoring record lows for viewing levels as their audiences continued to meander off to other alternatives -- the VCR, the Nintendo game, or to basic cable channels, one of the few areas of TV to show any growth.

As if that weren't enough, early in the year, Nielsen reported 4 million viewers missing and unaccounted for. They hadn't gone to any TV alternatives, so what were they doing? Reading? Conversing? Writing rap songs? It was a hopeful sign for everyone but the television industry.

When the fall TV season premiered in September and October, viewers turned blind eyes to most new shows. For one thing, the year's best new series had already premiered: Fox's funny, sneaky-satirical animated sitcom "The Simpsons" in January (following a pre-series Christmas special that aired in December 1989); and, on ABC in April, David Lynch's dark and goofy "Twin Peaks," which became to TV soap operas what "Ulysses" was to literature. Roughly speaking, of course.

"Twin Peaks" achieved only modest ratings success, however, and repeatedly throughout the year viewers rejected the more unorthodox network offerings. "Elvis," the ABC biographical series about the rock king's early years, died a little-noticed death in the spring -- certainly much less noticed than the real Elvis's has been.

ABC's daring "Cop Rock," an attempt by Steven Bochco to mix urban realism with pop tunology, was all but hooted off the air in the fall, and NBC's "Lifestories," a mildly innovative docudrama series about medical adventures, was roundly ignored.

If "Simpsons" was the series of the year, the viewing event of the year was clearly "The Civil War," a courageously ambitious 11 1/2-hour documentary miniseries by Ken Burns that aired on PBS in September. In one swell fell swoop, Burns reinvigorated national interest in American history and, not incidentally, in public television, which has seen some of its identity and character lost to cable channels such as Discovery and Arts & Entertainment.

Cable, whatever its small gains in audience, continued in its anti-consumer tradition of minimum service and maximum tsouris. After months and months spent negotiating a cable act in Congress that would have made a stab at reform, the measure was unexpectedly shot down in the summer by Sen. Timothy E. Wirth (D-Colo.), acting, it was said, to protect the fortunes of cable interests headquartered in his state.

Near the end of the year, the Federal Communications Commission did announce plans to consider some form of cable rate regulation, however, suggesting relief for gouged subscribers may be in the offing, or the dimly distant offing anyway.

The death in October of CBS Chairman and founder William S. Paley seemed officially to end the three-network era, an epoch to be mourned for the kind of cultural statesmanship and sense of responsibility that, even in seeking greater and greater profits, Paley and some of his contemporaries brought to American broadcasting.

Now the networks were leaner and meaner, and at FCC hearings in December, facing dwindling profits as well as audiences, they lobbied for an end to the 20-year-old Financial Interest and Syndication rule that has kept them from making money off reruns of the prime-time shows they air. Fin-Syn, as the rule is nicknamed, was designed to limit network power. But limiting network power by such artificial means no longer seems prudent. Not at this juncture.

In fact, it seems ridiculous. Plenty of other factors have emerged to limit network power.

At the hearings, Richard Frank, president of Walt Disney Studios, claimed the networks' clout hadn't really dwindled all that much. "Perhaps whereas they were once 900-pound gorillas, today they weigh in at only 850 pounds," he told the FCC. Unfortunately for the sake of Frank's argument, Disney tips the scales at 849, so huge and profit-swollen that rumors circulated for weeks about Disney buying itself a network, with CBS or ABC the likeliest candidates.

Some changes in the Fin-Syn rules are a virtual certainty in 1991.

Not all the images zapped into our homes by television news this year were discouraging, despite the dominance of the Iraq story. In February, there were triumphant scenes of Nelson Mandela's release from decades of incarceration in a South African prison, with ABC's "Nightline" doing the best job of reporting the event.

In June, Mandela visited the United States, and that produced more hopeful imagery on TV, although panting efforts by reporters to lavish praise on Mandela -- and thus demonstrate they were on the Right Side -- got to be a bit much.

George Bush's television presidency didn't exactly glisten in 1990, what with the chief executive having to eat the words we once were entreated to read off his lips, namely, "no new taxes." Bush continues not only to lack eloquence in his TV addresses and appearances, but to come across as petty and churlish.

The departure of Margaret Thatcher as prime minister of Great Britain was especially to be mourned by American viewers who savored her impassioned and persuasive attacks on Saddam Hussein. Thatcher gave the world's outrage a voice that Bush could not summon.

Next to the Saddamathon telecasts and the lingering humiliation of the Barry sting, the two most notorious pieces of videotape seen repeatedly during the year were Ronald Reagan's testimony at the John Poindexter Iran-contra trial, and Barr's grievous "Banner" bummer, more offensive than any politically motivated flag-burning had been. Reagan's frequent memory lapses during the testimony were embarrassing to watch -- either in full on C-SPAN or in excerpts on other networks -- but he did look like a man with nothing to hide. Or at least like a man who has forgotten if he has anything to hide.

For bouncing Barr and her potbellied husband, Tom Arnold, the anthem incident was the low point in another year spent making spectacles of themselves, and it became hard to know where the joke ended and the pathetic disgrace began.

Surprisingly enough, when "Roseanne" returned in the fall, the "Banner" affair appeared not to have hurt the show's ratings, proving ... what? Perhaps that viewers will forgive anything of someone who makes them laugh. How else to explain the infernally frequent resurrections of Richard M. Nixon, another of which occured this year?

Of course, with the country slumping into a recession and with America seeming more and more irreversibly heading for war, we need all the laughs we can get. Maybe Nixon could be encouraged to appear on the "Roseanne" show. Or he could be drawn into "The Simpsons." Bratty Bart meets Tricky Dick -- a match-up made in heaven. Or some place like that.

In addition to the loss of Paley, two more deaths during the year hit television, and those who have grown up with it, hard. Mary Martin, who played Peter Pan in NBC's much-loved musical adaptation of the James M. Barrie play, died in Rancho Mirage, Calif., at 76; and Jim Henson, pied piper of puppeteers whose Muppets charmed several generations, died in New York City at 53.

Those who thought a bad year could not get worse were thereby proven wrong.

The 10 Best TV Shows of the Year 10. "Cop Rock" (ABC). 9. "Evening Shade" (CBS). 8. "Caroline?" (CBS). 7. "Killing in A Small Town" (CBS). 6. "Madonna Live: The Blonde Ambition Tour" (HBO). 5. "Eyes on the Prize II" (PBS) 4. "Weapons of the Spirit" (PBS). 3. "Twin Peaks" (ABC). 2. "The Simpsons" (Fox). 1. "The Civil War" (PBS).

The 10 Worst Shows of the Year 10. "The Big One: The Great Los Angeles Earthquake" (NBC). 9. "Good Night, Sweet Wife: A Murder in Boston" (CBS). 8. "Maniac Mansion" (Family Channel). 7. "Hitler's Daughter" (USA). 6. "The Old Man and the Sea" (NBC). 5. "Ferris Bueller" (NBC). 4. "Against the Law" (Fox). 3. "Comic Relief" (HBO). 2. "Over My Dead Body" (CBS). 1. "Treasure Island" (TNT).