Say what???
For my definition of “greatest” I am going to insist that the character transcend both geopolitical boundaries and eras.
Therefore, my nomination for greatest character in sitcom history would have to be Basil Fawlty or Homer Simpson.
The only reason I do not nominate Mr. Bean is that his show isn’t properly a sitcom.
Archie Bunker
Niles Crane (Frasier was good, but Niles was funnier)
Hawkeye Pierce
Jim Ignatowski
I vote Gilligan/Maynard G. Krebs.
I believe I got most (if not all) of the characters listed here. If someone wants to organize a tournament. I’m not familiar with a few of the shows but I tried to get every name.
Archie Bunker
Frazier Crane
Homer Simpson
Lucy Ricardo
Bob Hartley
Hawkeye Pierce.
Cosmo Kramer
Louie De Palma.
Eric Cartman.
Anthony Aloysius St John Hancock,
Harold & Albert Steptoe
Basil Fawlty
Dick Loudon.
Les Nessman
Jim Ignatowski
Dr. Zoidberg
Glenn Quagmire
Dr. Perry Cox
Barney P. Fife
Frasier Crane
Liz Lemon
Maynard G. Krebs
Eddie Haskell
Mary Tyler Richards
Laura Petrie
Jerry Seinfeld
Darryl and Darryl
Arthur Fonzarelli
Sue Ann Nivens
Niles Crane
George Constanza
Dwight Schrute
David Brent
Edmund Black Adder
Jackie Harris
Rhoda Morgenstern
Edith Bunker.
Ralph Kramden
Fred Sanford
Dick Solomon
Sophia Petrillo
Bill McNeal
Alf Garnett,
Jack Tripper
George Jefferson
Maxwell Smart
Sgt Bilko
Norm Petersen
Cliff Clavin.
Frink. Moyven.
Jack Benny.
Frank Barone
Marie Barone
Dan Conner
Cliff Huxtable
Sir Humphrey Appleby
Gob Bluth
Nora Batty
Colonel Flagg
Homer Simpson
Ned Flanders
Quagmire
Nelson
Felix Unger
Dr. Perry Cox
Al Bundy
Dwight Shrute
Maude Findley
Chef
Leopold “Butters” Stotch
Timmy
Martin Crane
Elaine Benes
Ed Norton
Sir Humphrey
Arthur
Lt. Colonel Henry Blake
Ted Baxter
Col. Wilhelm Klink
Oliver Wendell Douglas
Ted Crilly
Dougal McGuire
Larry David
Sally Solomen
Barney Stinson
Mr Gormsby.
Sergeant (Vince) Carter
Ernest T Bass.
Rick and Eddie in Bottom.
Robert Petrie
Daisey ‘Granny’ Moses
Bill O’ Neal in “News Radio.”
Frog in “Best of the West.”
Howard Borden in “The Bob Newhart Show.”
Johnny Fever in “WKRP in Cincinatti.”
Bowler in “The Adventures of Brisco County.”
Sgt Schultz
Patsy and Edina of AbFab.
Lisa Simpson
Mork
Carlton the Doorman.
Cliff Huxtable.
Gracie Allen
Alex P. Keaton
Gilligan
I made a mistake: It’s Bill McNeil (still not sure of the spelling). Sorry about that.
May have missed it, but I think I was the only one to nominate George Burns – there was a vote for Mr. Burns on The Simpsons – but ya know what? I think George would have nominated Gracie, too.
Is this a woosh Thing Fish, or did you not read page 2? 
No one has mentioned Cap’n Kirk or Spock
Whattabout Chris Stevens from Northern Exposure
Star Trek wasn’t a sitcom. It was a drama.
Chris Stevens was a great character and Northern Exposure was a great show but many people consider it more of a dramedy than a sitcom. I’d put him on the great sitcom character list.
Okay Star Trek wasn’t a comedy, but Shatner’s Kirk was certainly comical.
I would say Fraser or Niles, but I think the characters were great due mostly to incredible writing - probably the best writing ever in a sitcom.
I agree with a previous poster for best ensamble casts being Taxi & Barney Miller, but I’d add Cheers and WKRP.
Archie Bunker gets my vote mostly because his character was more complex than some of the others mentioned, but Dick Soloman and Basil Fawlty have to be in the top 10 also.
But Archie did! He was popular in all corners of the U.S.
Ahhhh…you are talking about furriners. What do they have to do with anything? When was the last time a team from England won the World Series…huh huh!!!
I rest my case.
Kingfish from Amos and Andy.
George was the straight man to the amazing Gracie Allen…
As George Burns himself said, “I did have a talent - and I was married to her for 38 years.”
Les Nessman. (Turkeys, the humanity …)
It wasn’t funny but one of the Great Sitcom Moments was Mr Carlson (Gordon Jump) saying “As God is my witness, I thought turkeys could fly.”
I find it fascinating how Until Death Us Do Part and Steptoe and Son made such successful transitions to the US (as All in the Family and Sanford and Son respectively). Archie Bunker wasn’t a clone of Alf Garnett nor was Redd Foxx imitating Wilfrid Brambell. Instead, what was imitated was their role in society - Archie and Alf are both reactionary working-class jingoists but not bad men at heart. Sanford and Steptoe both represented life at the bottom of the economic foodchains in their respective countries.
That so many other shows have tried and failed to make the transatlantic jump merely highlights how good the copycat shows were - I can remember at least two fairly dire US Ab Fab clones and a Fawlty Towers remake with John Larroquette, as well as a UK Married With Children attempt (starring Russ Abbot) and a few others.
The only other successful pairing that I know of - and which is a pretty tenuous pairing at that - is Friends / Cold Feet.
There’s also Three’s Company / Man About The House. Semi-interestingly, both the former’s spin-off shows were based on the spin-off shows of the latter (Robin’s Nest / Three’s a Crowd, George & Mildred / The Ropers). In those cases, though, the US remakes were not exactly a success.
Also, though it was a (kinda) spin-off from The Golden Girls, Empty Nest was based on Father, Dear Father.
Another vote for Victor Meldrew.
As Victor’s wife Margaret put it, “You say Victor doesn’t care. You’re wrong! Victor cares too much! It’s what makes me love him, and what makes me want to strangle him to death.”
Another British character I’m fond of is Onslow, in Keeping up Apperances. “Here I sit COMPLETELY surrounded by NO BEER!” is a classic.