ESPN.com Top 20 Athletes 1995-2015 - ESPN

Bonds would go on to become one of the faces of baseball's darkest eras -- his milestones and career always, in some way, connected to performance enhancement. 7, 2007, Bonds passed baseball great Hank Aaron to stand alone as the all-time home run king. Said Bonds on the night the record fell: "This record is not tainted at all, at all. 18: Mia Hamm "When Mia came along, our game was nothing and nowhere," North Carolina's longtime women's soccer coach Anson Dorrance once said. Her 158 goals in 275 matches stood as an all-time U. S. best until June 2013. She won a gold medal in Atlanta in 1996, then again in Athens in 2004. Oh, and in between, there was that Women's World Cup victory in 1999. She was something and... 17: Floyd Mayweather Jr. Mayweather has stepped into the ring 47 times since 1996, and 47 times he has emerged victorious. But 47 times he faced an opponent not named Manny Pacquiao. until May 2, 2015. Until then -- and maybe after, too -- Mayweather's perfect record remains one of the Sweet Science's sweetest feats. 16: Usain Bolt His name is Bolt, which is appropriate, because he does. It took the Jamaican sprinter an Olympic-record 9. 63 seconds in August 2012 to take home the gold in the Summer Games' marquee track event, the 100 meters. In true Bolt form, he repeated his unprecedented 2008 Beijing feat, winning the 100, 200 and 4x100 relay in a single Games. Source: espn.go.com