I bought __Das Boot__ and __Downfall__ before I ever thought I would try to learn German. Having recently joined Netflix, I've been on a bit of a German movie kick. They have around 250 German movies! Here's what I've seen so far:
__Aimee and Jaguar__
__Good Bye, Lenin!__
__Sophie Scholl: The Final Days__
__Before the Fall__
__Triumph of the Will__
__Jacob the Liar__ (The original, not the Robin Williams remake)
__Naked Among Wolves__
__The BRD Trilogy: The Marriage of Maria Braun __
So far, my favorites are The Tunnel, Sophie Scholl, Rosenstrasse, Before The Fall, and The Experiment. I particulary recommend Sophie Scholl and The Experiment.
I also recently saw __The Lives of Others__ (now playing in theaters) and liked it very much!