Seachickens get my vote also. By a rather large margin. First, anyone who can rehabilitate Geno Smith is a God level coach. This is the opposite of Brady/Billichek. Tom Brady is still Tom Brady, but Russell Wilson may not have become "let-Russ-Cook" without Pete Carroll. Back-to-back National Champions and SB winner. 9 years of playoffs, and his defenses led the league in scoring for 4 consecutive seasons. One of only 3 head coaches to win a national title and a SB. One of 3! His defense and running game are perennially good if not great, regardless of talent.
I hate Pete because he's in our division, but this is the most underrated coach in the entire NFL. Bar none.