When you've already become the greatest Olympian of all time by setting an eight-gold-medal record in one Games, it's hard to top yourself. But Michael Phelps managed to do just that at his fourth and final Summer Games by setting a new Olympic standard as the most decorated Olympian ever: he has now collected 22 medals, 18 of them gold, in his competitive career. Phelps, 27, retired from the sport after his last race in London, but that doesn't mean he is gone; he committed to appearing in Rio de Janeiro in 2016 to continue to promote and, as he likes to say, grow the sport of swimming. While his medal moments were certainly memorable, keeping fan and financial support rippling in his wake is the legacy he hopes to leave in swimming.