Well, haven't seen that many Duran fights but read his bio. On the other hand, I used to have a career set of SRL.... It's tough because Duran had that longevity and fought well against far bigger men (though he lost to the best of them), but Sugar is 2&1 vs Roberto and beat the best he lost to. I'll go with Leonard but I might could be persuaded otherwise.
Duran because of longevity. SRL has a better record and it's admittedly a close call but Duran was 71-1 going into the SRL fight, was recognised as the best or at worst 2nd best lightweight in history, and beat SRL who later was recognized as the 2nd best welterweight of all time. Duran than goes on to give Hagler who is in the top 5 ATG middleweights a tough fight, and after loosing to Hearn, he goes and beats the fighter who beat Heans twice (Barkley), thereby earning a title in the middleweight division. To me the Barkley fight was one of the greatest achievement I've ever seen in boxing. Duran was older, shorter, slower, had less power, and was physically weaker than Barkley and yet fought a way to win that fight, by experience, a rock solid chin, a much underrated defense and enough power that if he landed combinations he could hurt Barkley, and that's exactly what he did and did so while giving up about 7 inches in height and who knows how many inches in reach. This from a guy who started out at 119lbs when he first turned professional. SRL beat virtually all the fighters of note during that period. Hearns *2, Benetiz, Hagler, Duran, the list goes on and on and had he fought more, I'd be picking SRL instead of Duran.
