Don't you guys just loved a wonderfully played twist ending? I just can't get enough. Here's some to get the ball rolling:

Evil Dead II: Whoa. That was so well done, especially the sudden cut to the credits. I might have put the original Army of Darkness ending here too, but since it wasn't final I won't.

The Usual Suspects: Need I say more? Kevin Spacey is SUCH a badass.

Dr. Stranglove: How's that for a thinker? This leaves you pondering the very things going on behind the Man's closed doors...