One of cinema’s most potent hallucinogens, Dario Argento’s witchy freak-out is a sustained spectacle of outrageously stylized violence and eye-popping art direction. When Jessica Harper’s doe-eyed American ballerina arrives in Germany to study at directress Joan Bennett’s renowned dance academy, she stumbles through the looking glass into a maze of mayhem, murder, and maggots. It all takes place in one of film history’s most outlandish haunted houses: a riot of demonic neon lighting, surrealist-baroque décor, and, oh yeah, that barbed wire room. Add the iconic, eardrum-shattering score by prog-occultists Goblin and you’ve got the most extravagant slasher movie of all time.