It's about a mental institution, where Jack Nicholson is sent because he wants to get out of prison work. Turns out that Nurse Ratched doesn't like him much and everything goes downhill after that. I will definately have to watch it again, it was a good film, but it was odd, and the end was a bit abrupt.
That is about as much detail as I can give without ruining too much for those who haven't seen it. I'm not that good at describing what happened in films without giving away the whole thing.
This only leaves a few films in my list to see...
-The Diving Bell and the Butterfly
-A Clockwork Orange
-The Godfather set