Here are my nominees by sport for the years 2000-2009. I gave it my best shot.
College football Tim Tebow
NFL Tom Brady
MLB Red Sox
College Basketball Tyler Hansbrough
NBA Lakers
NHL Detroit Red Wings
Soccer Brazil
Dictators I think it's been a good decade for Kim Jong Il and Putin
Music American Idol
Chess Gary Kasparov (hooray for essentric chess geniouses!)
Real life Obama..from community organizer to US President and hero with a Cult of Personality. That's pretty good
Politics SNL followed by Obama and Bush (hey 8 years is 8 years)
Religion Scientology has really increased their following I think