I vote for Lester.. outside of his first couple games (he has always come out rocky in April), he has been unbeatable as of late. 6-2, 2.97 ERA, and his 77 Ks are at least 17 more strikeouts than any pitcher listed above (Marcum has 60). If his stats continue in the same direction since the end of April, he will be your AL starter because he is the biggest star of anyone listed above besides Pettitte
Phil Hughes has also been very good, and yielded fewer hits than anyone in the AL with that many starts