Interesting question. Let's say:
1) Requiem of a Dream-just because it is such a beautiful movie that explores how quickly drugs destroy lives while having the best soundtrack that I have ever heard,
2) Alone With Her-this is a film surrounding a class of philosophy students whose final project is about survival in a nuclear holocaust and deciding who in the class gets to be in the bomb shelter and who has to stay outside and perish. This is a pretty cool movie that explores survival and friendship and love.
3) Sinister-Just because everybody needs at least one scary movie in the mix and Sinister was one of the better movies to come out in the last ten years.
4) 2:37-This is a Australian film that follows a bunch of troubled teenagers as the audience tries to figure out which one of the teens committed suicide. sad, depressing, with a suicide scene that will make even the coldhearted cry, this was a movie that I was really glad to see.
5) America History X-This movie showed how a skinhead turned around and realized that he was wrong in thinking all dark skin Americans were evil and instead ended up befriending one in prison and turning his back to the skinhead gang in prison. A really dark but well-done film that showcases racism and how gangs take vulnerable children and turn them into hate-filled members.