Lennox Lewis vs. Vitali Klitschko II.

I always thought Vitali would be the favorite in a rematch. Lennox was on the decline and time was against him and Klitschko was leading 58-56 on the scorecards at the time of the stoppage (the stoppage was obviously perfectly fair, the Ukrainian had a very bad cut, and it had been caused by a punch). Lewis was also a great champion and, despite his decline, was still competitive, but I'm going with Klitschko. Unfortunately, we'll never know how the rematch would have gone.