Bob Newhart - Suzanne Pleshette (The Bob Newhart Show), Mary Frann (Newhart), and Carlene Watkins (Bob)

Ted Knight - Georgia Engel (The Mary Tyler Moore Show) and Nancy Dussault (Too Close for Comfort)

Valerie Harper - David Groh (Rhoda) and Josh Taylor (Valerie/The Hogan Family)

Dick Sargent - Elizabeth Montgomery (Bewitched) and Priscilla Morell (as Elyse's Parents on Family Ties)

Conrad Bain - Rue McClanahan (Maude), Dixie Carter and Mary Ann Mobley (Differn't Strokes)

David Groh - Valerie Harper (Rhoda) and Joan Hackett (Another Day)

Nancy Dussault - Marty Brill (The New Dick Van Dyke Show), Ted Knight (Too Close for Comfort)

Dick Van Dyke - Mary Tyler Moore (The Dick Van Dyke Show) and Hope Lange (The New Dick Van Dyke Show)

Danny Thomas - Jean Hagen and Marjorie Lord (Make Room for Daddy)

Katey Sagal - John Ritter (8 Simple Rules for Dating My Teenage Daughter), Ed O'Neill (Married... With Children)

Well........

Beatrice Arthur was married to:

Stanley (The Golden Girls)

and

Walter (Maude)

______________________________________

Bill Cosby was married to:

Clair (The Cosby Show)

and

Ruth (Cosby)

_______________________________________



Nate

Katey Segal-John Ritter-8 simple rules & John Ritter-Markie Post-Hearts afire

Another one I forgot to add:
Dick Van Pattern - Diana Hyland (her death was so tragic and so young) and Betty Buckley (Eight Is Enough)

Drew Carey-Kate Walsh and Christa Miller (The Drew Carey Show)

Marcy (Married with Children) was married twice on the show. (Steve and Jefferson)