My heart wants to say El Radar, but I'd have to say George. He's just a more significant figure in the sport's history. When you add in the longevity... yeah, he has Will beat.
It comes down to Frazier x2/Norton Sr./only losing to Ali because of lose ropes/competitive showing with peak Holyfield (at 42)/Moorer (at 45) vs. Cervantes (at 17!)/Palomino/Duran/close decision loss to peak Tommy Hearns The young quick Benitez peaked early while the Joe Joyce sloth Foreman was still able to win a title while shot
I can't see much of a case for Benitez being greater, and I'm hands down the biggest Benitez fan around. He's my fourth favorite fighter OAT behind Tyson, Roy, and Duran. And I don't like Foreman - I think he's a fuckin phony. Both have amazing accomplishments - Benitez winning the title so young, and George regaining the title so old, but what weighs heavily for George is that he has arguably the single most impressive title winning performance in history. He then followed that up with an amazing destruction of an excellent Norton. Will doesn't really have performances THAT spectacular. He has the amazing clinic he put on Duran - but it was at 154, that's not the lightweight or welterweight Duran. He has the clinic he put on Palomino, but Norton P4P was better than Palomino. Then you factor in the HUGE gap in longevity - I'm just not seeing how Benitez has a greatness case. Foreman is without question greater. Better can be argued either way.
Foreman. Too historically significant to ignore. Not just his own significance but the role he played in building up other fighters too.
Under boxing rules, I don't rate George Foreman too high as a heavyweight great. But if it was a real fight, an MMA type of fight, I think he beats every other heavyweight champion in history.