Duran, obviously. Hands of Stone is on the same level as Robinson and Whitaker, arguably above even SRL and Pep. Mayweather has a nice skillset, but he is not close to that level, the history's elite club. Duran achieved one of the (perhaps even THE) greatest wins in boxing history by moving up to outfight a peak SRL and take his zero/title. Mayweather's best win was over Diego Corrales. Of course Duran proved to be a significantly higher level fighter.