AGE: 26
OCCUPATION: Tennis god
NUMBER OF TIME COVERS: 0
PREVIOUS APPEARANCES ON THE TIME 100: 1
PRO: One of the greatest players ever to pick up a racket, the Swiss champ has notched 12 Grand Slams and is expected to win quite a few more, barring the outbreak of some tennis ball–borne plague.
CON: The game becomes less fun and less challenging when you've been ranked No. 1 in the world since Feb. 2, 2004, and you don't have a proper rival. Which explains the friendship with Tiger.