Wow, thanks for all the recommendations, gaiz!
I've seen some of these already, and many that I have were excellent (notes on just a few below), so I'm psyched about the ones I haven't seen.
Cidade de Deus - (Netflix recommendation that I was very happy with, highly recommended)
the Wrestler- haven't watched it yet, but I loved all of Aronofsky's previous movies, with Requiem for a Dream and The Fountain being two of my absolute all-time favorites.
Eternal Sunshine of the Spotless Mind - (writer Charlie Kaufman is awesome--if you liked this, watch Synecdoche New York, which he wrote and was his directorial debut, and his best movie to date IMO)
Waking Life - (I really like Richard Linklater; loved Before Sunrise, Before Sunset, and A Scanner Darkly which was done in a similar visual style)
A Clockwork Orange ..."Stanley Kubrick is truly a genius." - Agreed.
So......how about any really, really unusual movies that you've thoroughly enjoyed? I would count The Holy Mountain among these--anyone seen this?