Bush was probably the best college back I've ever personally seen (I'm only 31 though). He made people look stupid in the open field, he wasn't just getting huge holes opened up by an NFL-grade line. Surprised he hasn't been better as a pro.
Barry Sanders was probably better but I wasn't really watching a lot of college football when I was eight years old. He ran for 2600 yards and 37 touchdowns his last year which I'm not sure I could do in a video game.