Gotta be Brady, but Vick is a legitimate candidate. His passer rating is only about 5 points lower than Brady's, and he's got 600 yards + 8TDs on the ground. And the Eagles are playoff bound.
That said, I don't think you can beat 1st round bye + longest no interception streak in history + highest passer rating + playing 4 more games + dominating in the snow etc.
On a related note, I'm sick of the Vick redemption love. He served his time and has a right to play again, but why in God's name is it so hip to like the guy now that he's back??? Wow, congrats on resuming your lucrative football career and not starting another dog fighting ring.