Given his total domination over his sport, and, given the overall athleticism demanded of a boxer, Mayweather is arguably the best athlete the world has ever seen. If as the pundits say, a superlative athlete comes once every century - witness Michael Jordan and Wayne Gretzky, then Mayweather is boxing's version. I would argue he is the overall superior athlete based on the number of skills that a boxer must possess in order to be highly competitive in the sport.
He's one of the better athletes in boxing history, but surely not the best. Roy Jones immediately comes to mind when I hear the words "athlete" and "boxer" in the same sentence.
Against B levels and one A class fighter who was past his prime (and probably a B+ by the time Floyd fought him). And don't forget that he struggled to beat Jose Luis Castillo in his first encounter.
Sugar Ray Leonard, Roberto Duran, Thomas Hearns, and Pernell Whitaker all exceed Mayweather's accomplishments and would beat him head to head. They all have better cases than Floyd does to be mentioned along side Jordan and Gretzky.
What about Shawn White dooood! I heard Sal Masekla call him one of the best Athletes ever, I almost puked. But ya Deion Sanders was simply amazing I actually mentioned that today to someone. I'm still with Lance though.
Good call - in terms of overall athleticism (strength, explosiveness, power, quickness, agility, and speed), he's one of the best I've ever seen in basketball.