As of 6-19-2010 no1 is Rafael Nadal. 2015 update: Novak Djokovic is the current No1
Former World No. 1 German female tennis player
The top Tennis player in the 1940's for the Men's side was Jack Kramer. The top Women's player during this time was Molla Mallory.
As he wanted to become world no1 tennis player he wanted to play... So he likes it.
As of November 2012, it is again Novac Djokovic. Federer held top position for the few months prior
Roger federer huge fan of him and Shawn Johnson. best atheletes ever!