Veselin Topalov
Topalov won the 2005 Chess Oscar. He was ranked #1 in the world from April 2006 to January 2007, and then had the second highest Elo rating of all time (2813). He regained the world #1 ranking again in October 2008, and officially remained #1 until January 2010, when he fell to #2 behind Magnus Carlsen.