What are some trippy movies?

Hey guys, so yeah, I feel I really need to start watching some more films. Lately, I have had a craving for being weirded out, by movies/music/art/etc.... Can anyone suggest some movies that classify as weird/trippy? Even if they're older and/or animated films that weren't meant to be trippy but are, i.e. Watership Down or Fantastic Planet, It'd be great if you could just jot down ALL of the ones that come to your head and I'll check 'em out. Thanks!