The speed. The medals. The poses. It could only be Usain Bolt, who electrified the London Games by becoming the first man to win the 100, 200 and 4×100 relay golds in back-to-back Olympics. Even IOC President Jacques Rogge, who initially balked at giving him “living legend” status, conceded that the six-time gold medalist “is the best sprinter of all time.”