Watching Psych-Out at this very moment (these are the things I watch when I'm home alone).
God, this movie is weird.
But it's from 1968 so I guess I can forgive it.
edit/spoiler: WOW what a terrible ending. What's with all these 60s movies having suuuuper depressing endings? It's symbolic, I get it, but it's amazing how quickly those credits start to roll after someone dies...