Newhart was so bent on keeping the ending a surprise that he actually cooked up a fake ending and fed it to the tabloids. In it, he died and went to heaven, where he met God, played by George Burns.
Roseanne also went out with an "it was all a dream" ending, but the results were more of a nightmare.
Up until the final episode, viewers had been led to believe that the blue-collar Conner family had won the lottery and that Roseanne's TV husband Dan (John Goodman) had survived a heart attack.
But in the finale, Roseanne reveals in a bizarre voice-over that the show's entire final season was all fiction that she wrote as therapy after Dan died. Her husband's apparent survival had been just part of her fantasy.
In the voiceover, Roseanne slips back and forth between herself and her character, talking about the origins of the show and her relationship with the characters, in a monologue that might have been even more confusing than the troubled star's personal life at the time.
When Roseanne says, "My sister in real life is gay," it sounds as if she's talking about her real-life sister. She's actually referring to her on-screen sister Jackie (Laurie Metcalf), who had suffered many man problems throughout the series.
Seinfeld (1998): Chief writer Larry David vowed never to allow Seinfeld the slightest drip of sentimentality, and the show went down making fun of itself all the way.
It begins with George and Jerry gloating over their good fortune after NBC picks up their TV pilot — a show with no plot, just like Seinfeld itself.
When Jerry tells his parents, his father mocks TV. "It's all crap on television," he says. "The only thing I watch is Xena: Warrior Princess — do you ever watch that?"
The show ends with Jerry and friends on trial for witnessing a carjacking and doing nothing to stop it. A parade of former characters testify to their bad behavior, and we last see Jerry, George, Elaine and Kramer in jail, bickering as usual. Cheers (1993): Sam and Diane flirt with marriage one more time. Woody is elected city councilman and Rebecca marries her plumber boyfriend.
But just as Sam agrees to move West with Diane, he realizes that the friends he's leaving behind at the bar are the closest thing he has to a family — and he can't go. He goes back, flicks off the bar lights and when someone tries to come in for a nightcap, he says, "Sorry, we're closed."
Happy Days (1984):
Seven years after Fonzie literally and figuratively "jumped the shark," he attempted something much harder — adopting an 8-year-old boy.
In the Happy Days finale, Fonzie seeks to adopt an orphan. Meanwhile, Joanie and Chachi decide after a steamy date that it's time to tie the knot, propelling the short-lived spin-off Joanie Loves Syndication, or something like that.
Cosby (1992): Cliff and Claire Huxtable literally dance off the air, waltzing off the set and out the studio door, as if to tell viewers, "Goodbye, this is the end."
The feel-good episode includes Cliff fixing the perpetually broken doorbell and the dyslexic Theo graduating from New York University. Gilligan's Island (1967): Even after 98 episodes, Gilligan never got off the island, and he and the Skipper never changed their shirts. The castaways were finally rescued years later in a series of TV movies, only to be stranded on the same island on a reunion cruise.