Not sure if they've been mentioned but these two are pretty good:

Dust to Glory (phenomenal aerial footage of the motorcycle class in the Baja 1000). This movie was done by Dana Brown, son of Bruce Brown who did The Endless Summer. Trailer: http://www.youtube.com/watch?v=_B6N-jXoFvM

Worlds Fastest Indian (land speed record at Bonneville), Anthony Hopkins is the main star.

Trailer: http://www.youtube.com/watch?v=3bu9dGRQvJY

The thing that is rather amazing about both these movies is that they are entertaining even to those who have never had much interest in the sport.