In no particular order
Lord of the Rings - one of my favorite trilogies of all time
Inglorious Basterds- The best acting I've ever seen in a movie
Indiana Jones and the Last Crusade- of the three (four I guess) my personal favorite, mostly because how well Sean Connery and Harrison Ford worked together
Saving Private Ryan- The greatest and probably truest (It's a word!) of war films.
The Empire Strikes Back- Who doesn't love it? Come on!
Pulp Fiction- Simply a classic
Reservoir Dogs- The above statement is also true.
The Godfather- Classic
V for Vendetta- Just the imagining of a movie like this placed into the context of our world made me enjoy it all the more. It was quite brilliantly done, especially for what I later found out to be a comic book movie.
The Untouchables- I've only seen this recently, but already I know a great one when I see it. I can't believe I've never seen it before. *ashamed*
The Departed- One of the best converging storylines I have ever seen in a movie. How it all played out just made me fall in love with the movie.
Pirates of the Caribbean: Curse- I didn't particularly like the sequels nearly as much, but Curse was such a fun movie.
Schindler's List- If I had a heart, this would be heartbreaking, powerful, but also a very well done film.
Goodfellas- The best of gangster movies
Men in Black- One of my personal favorites
The Dark Knight- The best Batman movie ever made
The Matrix- A movie that supplied just as much action as thought. Who knew you could do both? Well, probably a lot, but few tried.
Lawrence of Arabia- Nothing is written!