There are a lot of worthy candidates for this, but I would go with
and Darelle Revis
Reasons? On offense, I believe O-Line is kind of our missing piece and Joe Thomas is young and very good and he also gets it done on an otherwise horribly crappy offense (that gives him my nod in comparison to other great young tackles like Ryan Clady).
On defense, I picked Revis only because in todays NFL with the all the pass-friendly rules being a shutdown corner is incredibly hard and he and Nnamdi Asomugha are maybe the only two guys in the entire NFL who fit the bill right now. Yeah, a dominant pass rusher would be another great choice and I was tempted to pick someone like DeMarcus Ware, but there are a few more good pass rushers in the NFL but only two shutdown corners, so I picked one of them. Since Revis is younger, he gets my nod over Asomugha. Of course, I would take them both if available