RB Curtis Martin, New England Patriots/New York Jets:
The perennially underrated Martin ended his decorated career as the fourth-leading rusher in NFL history and was inducted into the Hall of Fame in 2012. He did make it to one Super Bowl with the Pats, but they dropped Super Bowl XXXI to Brett Favre and the Green Bay Packers.
He won the NFL rushing title with 1,697 yards in 2004, but a serious knee injury led to his retirement the following season. He had been an iron man up until that point in his career, missing only six games due to injury – an unheard of number for a running back. Martin ended his career as one of the greats with 3,518 carries for 14,101 yards and 90 touchdowns, but he never won the Super Bowl.