The short list:
Grace Kelly(Brett Butler) - Grace Under Fire
Karen Walker(Megan Mulally) - Will & Grace
Mary Jo Shively(Annie Potts) - Designing Women
Dawn French in the Vicar of Dibley
What sitcom characters do you love?
Mr. Bean played by Rowan Atkinson! He cracks me up!
Rob & Laura Petrie
Sanford & Son
The entire cast of WKRP in Cincinnati
Larry Appleton (Mark Linn-Baker) and Balki Bartokomous (Bronson Pinchot) from Perfect Strangers
George Costanza (Jason Alexander) and Cosmo Kramer (Michael Richards) from Seinfeld
Judge Harry Stone (Harry Anderson) from Night Court
Does The Simpsons count?
Archie Bunker
Father Mulcahey
Mork
Larry, Darrel, & Darrel
Reverend Jim
Hell yeah.
Homer, Homer Simpson he’s the great guy in history.
From the town of Springfield
He about to hit a chestnut tree.
(This is from memory so it may not be totally correct)
Coach from Cheers. The most lovable character ever to grace a TV.
Then if we’re counting Simpsons, I have to go with Homer, Comic Book Guy, Professor Frink, Apu, Ralph Wiggum, Lionel Hutz, Gil, Lenny and Carl, Smithers, and Lisa.
Don’t forget ol’ Gil.
Anthony (Meshach Taylor) - Designing Women
Dorothy (Beatrice Arthur) - The Golden Girls
Mrs. Krabappel - The Simpsons
Ozzy - The Osbournes
Shut up. He counts! 
Kramer, Mr Bean (although I don’t know if that’d be considered a sitcom)
I love the characters in “Scrubs”, but especially Dr. Cox.
Phoebe Buffay
Does an hour long comedy-drama count? I like Lorelei Gilmore from the “The Gilmore Girls”…what a well-written character!
Forgot a few…
Al & Peggy Bundy (Ed O’Neil & Katie Segal) - Married With Children
Marcy Darcy (Amanda Bearse) - Married with Children
I can’t remember her name, but whoever played John Forsythe’s wife on the short-lived The Powers That Be. She played an uptight, snobbish, Nancy Reagan-ish type to Forsythe’s philandering politician. Damn, she was hysterical.
Norm from Cheers.
And, QueerGeekGirl, I loved The Powers That Be! Remember Niles Crane played the daughter’s husband? He was so funny! The fabulous Holland Taylor played John Forsythe’s wife.
Well, if we expand into that, I also love(d) Tara and Willow from BTVS.
Joey from Friends.
the cast of Scrubs (except Elliot)
Coach, Kelly, Woody, Norm, and the guy from Melvilles from Cheers
If Ed counts as a sitcom, Dr Mike and Nancy Burton and Ed
Boomhauer, Bobby Hill, Cotton Hill, Khan (Sr), from King of the Hill
Jeremy Goodwin, Sports Night
Edward Montgomery, Dharma and Greg
Luther from Coach
I know there are a whole bunch I’m forgetting, but I’ll leave it there for now.
From “DSN” Benjamin Sisko, IMO, the best damn captain of the whole franchise. I’m probably in the minority, but I liked Morn…
kidding, I did like Quark though. And of course Jadzia Dax.
John Crichton and Aeryn Sun.
Kitty and Red Forman.
David Adison- just for the one-liners.
Edmund Blackadder
Samantha-from Bewitched- forgett the last name there.
Brenda from Six feer under.
Everyone from “Father Ted”
Diana and was it Tom from “Waiting for God”
The ditzy Phoebe from “Friends”
Sam Malone has to be the greatest sitcom character ever.