Actors on successful TV shows have a relationship with the same character that lasts longer than most Hollywood marriages. But that's not always the case. A few have returned to a long-running series in entirely different roles.

Dennis Franz, "Hill Street Blues"

Sal Benedetto (1983): A greasy detective whose lack of a moral compass led to his demise after a showdown with a robot negotiator.

Norman Buntz (1985-87): A greasy detective whose moral compass led to a beloved fan base and a short-lived spinoff series, "Beverly Hills Buntz."

Harry Morgan, "M*A*S*H"

Bartford Steele (1974): A loony general who inches the medic unit closer to the front and tries to court martial Hawkeye Pierce.

Sherman Potter (1975-83): A likable colonel who inches the medic unit closer to being a family and tries to calm down Hawkeye Pierce.

Renee Jones, "Days of Our Lives"

Nikki Wade (1982-83): Secretary for future Police Chief Abe Carver. Their May-December romance ends when he ditches her to lead a drug bust.

Lexie Carver (1993-2012): Wife of Police Chief Abe Carver. Their shaky romance ends when she gets a brain tumor and dies in his arms.

Neal Justin