OK, since I'm running the festival, they have to be bad AND weird.
I think I'd go with
MANIAC (1934)
GLEN OR GLENDA (1953)
ROBOT MONSTER (1953)
'MANOS': THE HANDS OF FATE (1966)
BLOOD FREAK (1972)
SANTA AND THE ICE CREAM BUNNY (1972)
ZARDOZ (1974)
DEATH BED: THE BED THAT EATS (1977)
THE APPLE (1980)
NIGHT TRAIN TO TERROR (1985)
BLOOD DINER (1987)
AFTER LAST SEASON (2009)
Thank you for adding AFTER LAST SEASON. That is a truly jaw-dropping experience.