Wow. I love Ken Burns. Did not know he did Ali as well. The Vietnam War, The Roosevelts and Prohibition by him are among my favorite documentaries.
Of the many recollections of Muhammad Ali -- books, documentaries, movies -- When We Were Kings is the most effective at capturing the spirit and the charisma of the man. The event it covers is well past his political controversies and banishment from boxing, and he is a big underdog going into the fight. It really is a brilliant movie.