For eleven years, Cheers was the audience go-to for the place where "everyone knows your name." It was a place of universal familiarity that made you laugh and made you want to throw something at the television every time Sam and Diane danced around their relationship.
Still, in all the time that the show was on, it featured plenty of memorable storylines - and recognizable celebrities to go with it. Nearly a dozen years on the air provided plenty of opportunities for various guest stars to make appearances on the show: 10 of which you forgot were even on Cheers, to begin with.
10 Thomas Haden Church
Church, known for Wings and various other roles, only appears for a few minutes, but his character Gordie Brown was significant. Following the sudden loss of her husband and the shocking revelation that he had a second wife, Carla is on a downhill spiral as she questions her life with her deceased husband.
Gordie shows up at Cheers following the disastrous funeral to deliver a letter to Carla from Eddie, explaining his terrible secret and that she was his true love. Gordie's not exactly the sharpest tack, nor is he the most sympathetic, but him carrying out his promise to Eddie by delivering the letter was a good deed - one that proves Eddie's sacrifice of his life to save Gordie's was worth it.
9 Sherilyn Fenn
Fenn made a brief appearance in a Season 4 episode as the cousin of the girl Carla's oldest son planned to marry. Carla spends much of the episode trying to deter her sixteen-year-old son from early marriage, even enlisting Sam to help her.
When Sam inadvertently finalizes the teenager's decision to marry, Carla thinks she can't change her son's mind until Sherilyn Fenn walks in, distracting Carla's son enough for him to instantly drop the marriage. It's different to see Fenn in a role that's not Audrey Horne on Twin Peaks, but even though her screen-time was brief, she nailed the part.
8 Alex Trebek
When Cliff ends up on an episode of Jeopardy!, it's the actual host Alex Trebek that experiences the jeopardy. Cliff lets his ego take over and bets everything he's won (he was the leader), only to get the final answer wrong and lose everything. Trebek later comes into Cheers, seemingly to apologize to Cliff for the way things went down.
It does cheer up Cliff, but Trebek confesses to Norm that since Cliff scares him, he made up his story. Cliff can be kind of scary in a pushy, know-it-all kind of way. Cliff was the perfect person to go on the game show, and Trebek did a splendid job delivering a comedic performance, possessing fun chemistry with Cliff. He could've been a Cheers regular.
7 Ethel Kennedy
The widow of Robert F. Kennedy made an appearance in the opening sequences of a Season 11 episode. Spotting her, Cliff grabs his camera and tries to get Norm to get a picture of him with Ethel.
Hilariously enough, Norm winds up giving the camera to Ethel and getting a picture with Cliff instead. They met Ethel Kennedy, and they have no photographic proof - though they can look back on the picture and remember who took it. It was a cool, subtle inclusion to have Ethel Kennedy on the show. Plus, she's a symbol of Boston itself, so it's a perfect fit.
6 Harry Connick, Jr.
Harry, who plays Woody's cousin Russell, comes to Boston for a new start in a Season 10 episode after he gets out of a long-term relationship. He's hired to be the piano player at the bar, which is cool as you get to see Connick's musical talents.
Trouble is, he soon becomes obsessed with Rebecca in more ways than one. Rebecca turns him away, but rethinks her decision and tries to convince Russell to give her another chance--only to find him painting a mural of Carla over the one he'd painted of her. He moves on faster than most.
5 John Cleese
Cleese, known for being a co-founder of Monty Python, makes an appearance in Season 5 as a renowned marriage counselor that Frasier met and befriended years before. Cleese makes the mistake of agreeing to a session with Sam and Diane, which leads to him declaring the two are positively unfit for each other.
Sam and Diane, at Diane's insistence, continue barging into Cleese's hotel room to tell him why he was wrong until Cleese snaps and declares on tape that he was wrong, though it's clear he's only saying it to get the couple to leave him alone. Ironically, it was Diane who wanted a session with him, to begin with. And really, she keeps bugging him because she needs to hear from him that his assessment of her and Sam was completely wrong, which she gets. Cleese played his part so well he received a Primetime Emmy Award - one that was well-deserved.
4 Johnny Carson
Legendary television show host Johnny Carson appears as himself in a Season 10 episode. When Norm fabricates an acceptance of one of Cliff's jokes on behalf of The Tonight Show, Cliff takes the initiative to buy himself, Norm and his mother tickets to see Johnny perform the joke live. It seems Cliff has a bad time with hosts of any kind, be it Trebek or Carson, as he's offended when Johnny "botches" his joke.
Hauled off by security, Cliff misses the chance to be on TV with Johnny, but his mother and Norm get to be on the show. Johnny Carson was filled with talent, and it was fun to see him interact with the Cheers characters while playing himself and telling Cliff's bad joke (which goes to show Johnny could make everyone laugh regardless of a joke's quality).
3 Emma Thompson
Actress Emma Thompson plays a famous children's entertainer, Nanny G, who happens to also be Frasier's first wife. She's fun, colorful and has a beautiful singing voice. She seems perfect until she recognizes Frasier in the audience and passionately kisses him in front of his wife Lilith and son Frederick.
She later apologizes to Lilith, but the way she shamelessly flirts with her ex-husband says otherwise. It takes a vicious catfight with Lilith for Nanny G to get the message, though she does leave a doll behind that sings her phone number so Frasier can contact her. That is until Lilith rips the doll's head off.
2 Christopher Lloyd
Lloyd is well-known for his eccentric array of characters, including "Doc" Brown of the Back to the Future franchise. Guest-starring as the unconventional painter Philip Semenko, he finds "the face he's been looking for" in Diane and wishes to paint her. This upsets Sam, but Diane goes behind his back and allows Philip to paint her anyway.
The funny thing is, Philip warns Diane the entire time that if he paints her, it will drive a permanent wedge between her and Sam. Turns out he was right, as Sam and Diane break-up in the second half of the two-part episode. Lloyd played the party immaculately, and it was impressive that his character could read into Sam's and Diane's relationship so well despite the fact that he didn't know them at all.
1 Lisa Kudrow
Before she was Phoebe on Friends, a brunette Lisa Kudrow guest-starred as Emily, an actress that helps Woody embrace his acting skills in a Season 8 episode. Emily is a professional actress that uses method acting to try to make Woody more comfortable with romance scenes to any degree.
She keeps failing, until she reminds Woody that if he can't say he loves her to her face (for the purpose of the play, of course) then he'll lose the part. The secret to acting: fear. Or at least, in Woody's case it is, and Emily helped him find his motivation. Even before she was Phoebe, Lisa seemed to find her niche in playing positive, upbeat characters looking to help others.