 Jason Athens in ABC News. ESPN ranking the top athletes of this century, and some sports fans may be surprised by their picks. Tom Brady, the seven-time Super Bowl champ, landing at number five on the competitive leaderboard. Serena Williams outranking him, taking the second-place spot on the list. The number one top athlete of the 21st century is swimmer Michael Phelps, the 28-time Olympic medalist ranked above all else, according to ESPN. I'm Sherry Preston, ABC News.