This one is not even hard. There were only two real candidates all season: Johan Santana and Roy Halladay. Halladay got injured on September 20 and missed his last two starts, which hurt him. But even without that, Santana was the man (again). Sure, you could look at the fact that he led the league in wins, strikeouts, and ERA. Or you could look at his 26-8 adjusted record (compared to 21-9 for Halladay).
But this is one case where you don’t even need statistics — Johan Santana is simply the best pitcher in baseball, and certainly the best in the American League. He wins his third straight Cy Young Award this year. (Wait a sec, you’re telling me that Bartolo Freaking Colon won last year? Even though anyone with enough of a brain to understand exactly how important win/loss records are/aren’t knew Santana deserved it? Well, excuse me while I pretend that never happened. It’s hard to take the Cy Young Award seriously if I can’t ignore that.)