Assuming you are just going to show the knockouts and not whole fights right? Either way, Gonzales vs Mares is a nice short one from recent times. Toney vs Nunn, Buster Douglas vs Tyson, as Titofan said Tyson-Berbick, but also Tyson Spinks as that was technically for the lineal title. Foreman-Frazier, Ali-Foreman, Foreman-Moorer. Tarver-Roy Jones is a good one. Schmelling-Louis for an oldie.. Chiquita Gonzales vs Carbajal? Think that was a unification but those should count right.. Hatton-Pac then even? Maybe Nunn-Kambalay? Can't remeber on that one, but so so many obviously.