Floyd - 130 Manny - 135 (if he had stayed there) Toney - 168 (when he was in shape) Jones - 168 Duran - 135
In terms of career? Well Lightweight for Floyd, Featherweight for Manny, Super Middleweight for Toney, Light Heavyweight for RJJ, Lightweight for Duran.
Mayweather - 130lbs Pacquiao - 135 or 140lbs, sadly he didn't stay long enough at either Toney - 160lbs IMO, but really not much between his best in-shape motivated performances at 160 & 168 Roy Jones - 168lbs without a doubt Duran - 135lbs, obviously