Nikki to The Art of Being Nick

Married…With Children's Marcy Rhoades(D'Arcy) appeared in an episode of Nikki

Bud Bundy from Married...with Children showed up on Parker Lewis Can't Lose

Andrew Keaton from Family Ties appeared in an episode of Parker Lewis Can't Lose

Family Ties had a failed spin off called The Art of Being Nick focused on Mallory's boyfriend Nick Moore.