Verotika
Someone already suggested Glenn Danzig's Verotika, but I am doing so again to offer three reasons:
The gross incompetence of this movie on all levels (direction, script, cinematography, acting) is a rare and beautiful thing. We expect such boners here and there in the movies that get a RiffTrax treatment, but Verotika has it all and manages to demonstrate that it can get nothing right through the entire run.
The movie is broken into three shorts with no throughline, because the auteur was too lazy to go into production with more than a few notes on a page: One story about a sex worker with eyes on her boobs who manifests a murderous monster, one story about an exotic dancer who steals faces, and one story about a medieval noblewoman who likes to take long baths in tubs of blood. There is no meaning behind these stories. No characters. No significant grossout factor or jump scares. They are like the scrawled panels of an amateur comic book created by a lonely adolescent.
The plots of the three shorts are insane, when they exist at all, but the execution is where the bad-good gold is. Until you've experienced the French accent from Glenn's pornstar ex-girlfriend who plays a sad sex worker with eyes where her nipples should be, you haven't lived, baby.