For me, in no particular order:
1. American Psycho (Only if you're over 18)
2. The Dark Knight (IMO, the best superhero movie ever made)
3. Watchmen (Good, but falls just below the Dark Knight)
4. 300 (Great action flick if you're into that sort of stuff, and again, 18+ only)
5. Fight Club (What can I say? Noone talks about fight club...)
6. Avatar (The 3D in this changed my life)
7. Shutter Island (Mind = blown)
8. Lord Of the Rings 1,2 and 3 (Yes, I know it's 3 movies technically, but if you watch one, you must watch all of them!

9. Thor (I was really surprised by this one, turned out to be ALOT funnier than expected)
10. the Shawshank Redemption (Just a purely awesome movie. Words cannot describe how good it was
