Mine are;
Ann Romano-One Day at a Time
Potsie Weber-Happy Days
Mr. Kimball -Green Acres
the second Becky-Roseanne
Kirk Devane-Newhart
Beau- Welcome Back Kotter

Abby Lockhart (ER)
Carol Vessey (Ed)
John Burns (Taxi)
Diane (Cheers)
Max (NewsRadio)

Steve Urkel - Family Matters
Gilligan - Gilligan's Island
Cindy - The Brady Bunch
Latka - Taxi
Fran - The Nanny
Laurie - That 70's Show
Kathy Greenwood - Whose Line is it Anyway (not a sitcom, but I cannot stand her)

flip (happy days) yep just one I can think of right now!.

Robin(Cheers)
Simka(Taxi)
John(Taxi)
Susan(Seinfeld)
The Pigeon Sisters(The Odd Couple)
Pam(The Cosby Show)
Sam & Maggie(Diff'rent Strokes)
Beverly Ann
Pippa }(Facts Of Life)
Andy
George

Evan-Cheers
Max-Newsradio
Tori-Saved By The Bell
Eddie LeBec-Cheers

Latka ("Taxi")
Just about all the characters from the "Taxi" show
Granny ("The Beverly Hillbillies")
Maude ("Maude")
Archie Bunker ("All in the Family"/"Archie Bunker's Place")
Mike Stivic ("All in the Family")
Barney ("All In The Family"/ "Archie Bunker's Place")
Mr. Bentley ("The Jeffersons")
Rhonda Lee ("Laverne & Shirley")
Bobby Brady ("The Brady Bunch")
Cousin Oliver ("The Brady Bunch")
Howard Spague ("The Andy Griffith Show")
Fran ("The Nanny")
Grady ("Sanford and Son"/"Grady")
The 2nd Lionel Jefferson ("The Jeffersons")
Mrs. Howell ("Gilligan's Island")

That is all I can think of for now.

Leo Markus (Will & Grace)
Diane Chambers (Cheers)
Lucy Ricardo (I Love Lucy)