Tommie Frazier and Vince Young
These are actually the first two that came to mind for me.
I have never cared for Nebraska football, but Frazier's performance against Florida was one of the most memorable and entertaining for a non-K-State player that I can remember.
I have been consistent in my respect for Mack, but VY is THE reason he won a title at Texas. He was ridiculous in the NC game.