My 3 favorites would be
1. the last 30 secs of round 5 rumble in the jungle when foreman had beat the **** out of his ribs early in the rounds and was swinging in the last 30 secs and Ali smashing him and showed at that point that he was in control of the fight and ends it with foreman in a headlock and ali stickin his tounge out.
2nd would be tyson-thomas knockout, tyson had really worked in the early rounds to knock the iron chined thomas out and really digged deep to end that fight with a ko, just shows how tyson was always in there to finish you, never played it safe with a descision. That kind of tyson was far more focused than any other, id like to see any other fighter with a bowling ball for a head survive that attack
Last one would be holyfield surviving bowes attack in round 10 in the first fight, theres so many great moments from holyfields fights to choose from but those uppercuts he took from bowe were solid and its unreal how he stayed on his feet