Such a tricky question to answer. I put Ali v Foreman simply because it completed Ali's Legacy in my book. Underdog, so called finished, going in with a young beast that had just Eaten Frazier up to become champion in a manner so brutal it had never been seen before in a World HW title fight. People were even worried for Ali pre-fight that he might get seriously hurt.
and When I say Completed his legacy, the Spinks rematch to be the first 3 time World HW Champ meant nothing to me . Simply because if he hadn't lost his title to a 7 fight novice (albeit a great novice) , he wouldn't have had to regain it!