1) Goodfellas - A classic in every regard. This is a movie I can watch at any time, but only from the beginning. It's a fantastically told story with great acting and great directing by Scorsese.
2) Inglorious Basterds- Once again, a movie I can watch at any time. It's a great comedy, but the emotional bits (Shosanna in particular) are done in a way that only Tarantino can provide
3) Fight Club- I don't think I even need to explain this one...
4) The Departed- Another 'any time' movie. Great music, great directing, and great performances by all involved (Nicholson is the fucking king in this movie, and Ray Winstone proves how amazing an actor he is)
5) One Flew Over the Cookoo's Nest - Nicholson's best work, in my opinion. It's an extremely likable film with a light heart and a dark mind. It's also beautifully written and acted, painting even the smallest characters with detail and personality.
6) Gran Torino- Proving Eastwood can be a badass at 80, sing, produce, and direct. It was also the first film to make me cry in a while.
7) Shutter Island- Psychological horror done right by Scorsese and DiCaprio. An interesting fact: Two of the people who play guards have played murderers in other movies (Buffalo Bill, the Zodiac Killer), A few of the prisoners have also played murderers in other films (Rorshach, Elias Koteas). Also, hearing Ben Kingsly say "Why you all wet...baby?" makes me laugh every time.
8) The Shining- Stanley Kubrick makes you his ***** in this movie. Absolutely terrifying.
9) The Good, the Bad, and the Ugly- Classic Eastwood. Plus, there's Tuco, who is an entire movie within a character. Plus, it portrays the Civil War better than most American movies do.
10) V for Vendetta- I'm surprised this is so high on my list, but after thinking about it, it makes sense. It's beautifully acted, beautifully written, and all around beautiful film. It portrays its message in a perfect way, and I just love the world it created. It was able to do so much in so little time.