Now, this award was definitely the closest one between the PatriotsLife writers (see @CultOfBelichick), but Wilfork just edges it.
Despite Rob Ninkovich's transition to a defensive playmaker, the award goes to Wilfork, as he performed at a consistently high level throughout the year, mainly as a run stopper. The Patriots were very good at stopping the run this season, allowing just one RB to rush for over 100 yards on them all year, and this was one of the key reasons the Patriots defense performed a lot better this season.
Add to that Wilfork's leadership ability. He and Jerod Mayo have stepped up as leaders of not just the defense, but of the team, as it's gotten very young very quickly. His anchoring of the D-Line has ensured that the young playmakers around him have become free to make some big plays, particularly a guy like Brandon Spikes, who has really stepped up this year.
Wilfork might not jump off the page statistically, but his constant impact throughout the season have made him one of our key players, and was definitely up for the MVP award, but he was certainly our best player on defense this year.