Alex Smith
Most NFL quarterbacks don’t receive the chance to overcome bust status. Smith had a nightmarish experience in San Francisco before he achieved one of the greatest career revivals ever. Things changed in 2011 when Jim Harbaugh entered the picture and coached him properly (via ESPN).

Suddenly, the Niners reentered the playoffs and Smith appeared to be a functional quarterback. But he left San Francisco for Kansas City where he helped Andy Reid through his early years with the franchise. Then he had one of the great comeback stories when he recovered from a horrible broken leg in Washington.