Really hard question to answer. Lots of tough guys, would be very hard to pinpoint the toughest, there's just been so many throughout the history of boxing.. Basillio, Marciano, Robinson, Hagler, Ross, Ali , McCullough, Dempsey, Greb to name a few. James J Corbett Vs Peter Jackson lasted 61 rounds. Thats's tough. Honarable mentions to men like Arthur Abraham and Marion Wilson..
Duk Koo Kim deserves mention. Lots of very tough guys fought and died, because perhaps they were too tough.
morales....#1 vazquez...maeruez brothers and pacman #2 #3 gatti & chavez #4 barrera..mosley..margarito #5 tito odlH..ward 6th finito..duran..ray leonard..calzaghe
LaMotta, Gatti, Chacon, Chavez, Ward, Holyfield, Mancini, Deuk Kim... So many to name, those come to mind first for me. I don't put Duran in there because of the No Mas incident...
How did I not mention Tapia? My boy and I were just talking about him yesterday.. Ya hes on the list..