1. Floyd Mayweather Jr.
43-0-0 (26 KOs) | Welterweight
Mayweather said on Dec. 5 that he plans on fighting twice in 2013: on May 4 and Sept. 14. The most likely opponents are Saul "Canelo" Alvarez and Robert Guerrero. A long-fancied megafight with Pacquiao further lost its luster with the Filipino's knockout loss.