Single greatest player? That's a very difficult decision for me because I'm torn between Brandon Avalos, Mark Guillon and Brandon Brooks.
Seriously, I think Lane Bearden has to be on that list. He was a special player for Alabama given his circumstances.
Being born in 1991, I have not seen some of the legendary players. I struggle to say who was greatest when I look at players I saw play compared to guys that had already retired from the pros by the time I was born.
Also, the change in style of play causes folks to have a different look at players. AJ is going to every career passing record in 2013 unless he has a major injury. No arguing AJ is a great player; however, is it fair to use his stats to judge his greatness compared to a QB from a generation of less passing?
A list of the greatest players from each era (defined as you like) would probably be the best thing to do. Such a list gives each player the fortune of being compared to players from that era of football. The guys that had to play both ways cannot be compared to guys from today's era of football. Neither can players from the period of Freshmen not being allowed to play on the squad.