The best movie ending I've ever seen is from a movie called 'The Takers' (I think). I only watched it because the description reminded me of an episode of the Simpsons (bikers move into a house, terrorize the people who live there), thinking they might have gotten some inspiration from the movie. It really wasn't anything like the episode (aside from the bikers), but it was still pretty good.
Basically, the bikers follow these 2 women home, find out that the one girl's husband will be out of town for a week, and have their way with them. I guess the husband comes home early, though, finds all 4 of them sleeping in the same bed and shoots the bikers. Then he walks towards the camera, says his line, fucks it up and starts laughing. Every member of the crew then walks into the frame and start talking amongst themselves and with the cast. I wish I hadn't deleted it off my DVR.