So many bio pics to pick from, I really don't know. The first one that comes to mind is Lenny (1974) The Lenny Bruce story. I've seen that a lot, it stars Dustin Hoffman as Lenny Bruce and was directed by Bob Fosse who also did All That Jazz (1979). yeah, if I had to pick my favorite, it have to be Lenny. Good film, if you haven't seen it give it a try.