In no particular order:

Scarface
The Matrix (just the first one)
LA Confidential
Pulp Fiction
The Usual Suspects
This is Spinal Tap
Goodfellas
Carlito's Way
The Godfather films
Star Wars (the good old ones only)
JFK
Fear and Loathing in Las Vegas
Alien & Aliens
Leon
The Good, The Bad and The Ugly
Terminator 1 & 2
Fight Club
The Lord of the Rings films
Last of the Mohicans
Fargo
Lock Stock.

Sorry, probably quite a few over 20 films, but so hard to choose.