Choi is my favorite because he drives it so damn straight, and he's probably the hottest player in the game at the moment. He's pretty much fearless when he gets around the lead, and the next logical step in his career is to win a major. Also, I'm not impressed by the recent play of the usual suspects (Tiger, Phil and the rest).
Mahan is my dark horse because absolutely no one expects him to win, and I liked his fire in winning the Travelers. He's also first in the TourÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s total driving statistic, which combines distance and accuracy, and Carnoustie's fairways are famously tough to hit.