Horrorish:
Cube
Funny Games
Oldboy
Elevated (if you only have 20 minutes to kill)
Repo! The Genetic Opera
Action:
Bangkok Dangerous (original version)
Commando
Rampage (by Uwe Boll)
All-around great:
Glengarry Glen Ross
Give 'Em Hell, Malone!
Brick
For fun:
The Wicker Man
Frogs (challenge: try and make it through the whole movie)
Gay******s from Outer Space
Survive Style 5+
Street Fighter: The Movie
Michael Jackson's Moonwalker
Documentary:
Young Yakuza
Grizzly Man
Catfish (I hear this obscure documentary inspired a TV show now or something?)
Enjoy your movie!