I always thought Robin Evans as Carol from One Dark Night was an OK bitch. Anybody who kicks E.G. Daily out of a car and makes her walk in a tunnel is a bitch. "You named it, you claimed it!!" And I always loved Eileen Davidson as Vicki in House On Sorrority Row. Although it was a small part Diane from Slumber Party Massacre was a bitchy snob. Pedro's girlfriend in Tombs of the Blind Dead. Another small part but quite bitchy and troublemaking. Maybe you can call them "campy bitch" roles, but Joan Collins in Empire of the Ants and Joan Crawford in Berserk! are fun to watch. It's probably hard to beat Judy from Sleepaway Camp.