Ryan Lochte

He won gold in the 400m individual medley at Beijing 2008, beating Phelps directly—a feat that ranks as the only loss for Phelps in that event at Olympics. At his peak, Lochte held five individual world records simultaneously, including a 1:54.00 in the 200m IM, and was named World Swimmer of the Year in 2011. His versatility across backstroke, freestyle, and IM events rivals Kristin Otto's range, but his medal total is 100% higher over a longer career, spanning 12 years from 2004 to 2016.