23. Manny Pacquiao
Yet again, like many individuals on this list, Pacquiao has remained active for far too long. Still, at his pinnacle, Pacquiao (59-7-2, 38 KOs) dominated boxing and became one of its most decorated figures.
Pacquiao, an eight-division titlist who the BWAA named its “Fighter of the Decade” for the 2000s, was the world’s premier pound-for-pounder from roughly 2006 to 2012. Among others, the speedy southpaw outclassed Juan Manuel Marquez, Timothy Bradley, Antonio Margarito, Érik Morales, Miguel Cotto, Oscar De La Hoya and Ricky Hatton. The 39-year-old Pacquiao is slated to face Lucas Matthysse on July 15.
Image Source: Chris Farina/Corbis via Getty Images