Replying to My Current Movie Collection - What to add?

So over the past couple months I have built up a decent collection of some of my favorite movies using torrents and my handy external hard drive. Judging by the movies I already have, what would be some other movies to Add?

The List:
Kill Bill Volume 1
Kill Bill Volume 2
Fight Club
Shawshank Redemption
Green Mile
A Clockwork Orange
Boondock Saints
Donnie Darko
Four Brothers
Green Street Hooligans
Lock Stock and Two Smoking Barrels
The Wall
V for Vendetta
The Butterfly Effect