Awh man. Whoa. That's a hard question.
I have seen a lot of movies where I have said "damn, that was good!".
I think the easiest way to answer this is to just make a list..
Wanted
Live Free or Die Hard
Saw series
Bourne series
American History X
Okay I think those are the top 5 (movies/series of movies)
EDIT: Alright yeah I just have to add I am legend to that..