You missed Ruthie Cohen (101 episodes), George Steinbrenner (16 episodes), and Elliott Lippman (11 episodes). Also, what source did you use? My source lists 48 episodes for Newman, 29 for Frank, Estelle, and Susan, 24 for the Seinfelds, 22 for Peterman, 15 for Leo, 12 for Wilhelm, and 11 for Puddy.