Most Recognized Person?

An ongoing debate between my father and I centers on this question: Who is the most well-known/recognized person in the world? George Bush? David Beckham? Barack Obama? All good bets, but we have come to the conclusion it's probably someone else: Tiger Woods.

He has been on the world stage for longer than Bush. Truly dominates a sport unlike Beckham. Also, he has the fascinating racial background of Obama. What do you think? Other ideas?