Manny Pacquiao is the first boxer in history to win major world titles in four of the original eight weight classes of boxing: flyweight, featherweight, lightweight, and welterweight. He was named "Fighter of the Decade" for the 2000s by the Boxing Writers Association of America (BWAA), WBC, and WBO. He is also a three-time Ring magazine and BWAA Fighter of the Year, winning the award in 2006, 2008, and 2009; and the Best Fighter ESPY Award in 2009 and 2011.

Floyd Mayweather held multiple world titles in five weight classes and the lineal championship in four weight classes (twice at welterweight), and retired with an undefeated record of 50–0, surpassing Rocky Marciano's record of 49–0. As an amateur, Mayweather won a bronze medal in the featherweight division at the 1996 Olympics, three U.S. Golden Gloves championships (at light flyweight, flyweight, and featherweight), and the U.S. national championship at featherweight.