Continuing the horror bent: Suspiria, good, 70's, high 70's style, Art Nouveau, vivid colors and imagery. The version I found, a little uneven on sound, and the overdubbing of the language is rather unconvincing, artificial, seems a little unsynced, but overall - definitely not the best, but you can see how it influenced later movies.
Trivia: I'd always wondered what became of Jessica Harper - the lead from "Phantom of the Paradise" - well, this was her next big thing. She turned down Annie Hall for this.
Curious.
LINK(Warning, Spoilers): https://en.wikipedia.org/wiki/Suspiria