Boy, it's so hard to single out just one.
Honestly, it feels like everyone improved. Wilson (probably don't count), Michael Robinson (seemed to become more of a weapon - even though he was pro bowl last year), Unger, Okung, Breno, McQ, Miller, Anthony McCoy, Golden, Richard Sherman, Jeremy Lane, etc.
I love our team. Now it's just about raising the level of talent at key positions, or tweaking the scheme a little bit (generate a pass rush).