This has got to be the best boxing doc I've seen since Ring of Fire: The Emile Griffith Story. http://thegarv.com/2009/04/08/mike-tyson-documentary/#more-6711
For those that haven't seen it, Tyson narrates the entire film and doesn't try to put himself in a positive light. He just attempts to frame his actions in terms of how he was thinking and feeling at the time.