I know this is highly subjective, but pleas be as unbiased as possible when making your picks and do consider factors outside of the actual fight. example Johson being the first black heavyweight champion - think about how this was never considered possible for a black to challenge for the title, let alone win it. Johnson chased Tommy Burns across the world just for this fight to be made.
Might be Frazier beating Ali. Might be Foreman's come back., or Tyson unifying so early in life. Good question, i enjoy this one. Curious to see if a concensus forms as it usually does on a forum like this.
Probably when Tony Galento ate 50 hot dogs for a $10 bet about half an hour before getting in the ring and KOing Arthur DeKuh in 4 rounds.
Leon Spinks defeating Muhammad Ali,,,,,,, An amazing feat, as Leon also had to defeat a Referee and '2' Scoring Judges, plus a 'boat-load' of back room money men.
I honestly couldn't pick one. Gun to my head I say Louis dominating a decade but it's barely above others. Ali cleaning out the strongest division in he history is up there. Tyson going on his rampage is up there. Lewis reunifying the titles, Sullivan ruling for a decade, Johnson clearing out his era, foreman knocking out moorer, vitali and his amazing comeback. Wlads current level of dominance is almost unprecedented. The division is very rich in history and there's so much to impress but gun to my head I'm going Louis.
Other possibilities would include: John L Sullivan unifying the bareknuckle and gloved title claims to establish the primacy of gloved boxing. Jack Dempsey drawing the first million dollar gate. Joe Louis dismanteling the colour line. George Foreman winning back the lineal title in his 40s.
The greatest VICTORY was Ali beating Foreman. Greatest ACHIEVEMENT was Johnson even getting the incumbent champion in the ring let alone actually winning ! The amount of racist **** around in those days was disgusting.