Pink Flamingos
Oh, come on! Don't tell me a Pink Flamingos/Batman movie wouldn't eighteen shades of awesome! Batman in a death match with the Pink Flamingo, played by Waters (or maybe Steve Buscemi?), and "the Filthiest People Alive", Cotton, Crackers, Eggman, Miss Edie, and Divine, as Harley Quinn to Flamingo's Joker!