Jim Plunkett, Patriots
He was awful with New England but salvaged his career with the Raiders. With the Patriots, Plunkett completed less than half of his passes and threw 25 more picks than touchdowns. But he won two Super Bowls and posted a more respectable 80 touchdowns against 81 interceptions with the Raiders. He is the only Hall of Fame-eligible QB to win two Super Bowls and not be inducted.