It's a tough call. You have Stats, MVP's, SB MVP's, overall wins, of course SB wins too, Clutch factor too. I think it's between Montana, Brady, Unitas, Elway, and Peyton as far as greatest ever. Of course with Unitas I factor in NFL Championships because he played a lot of his career before the SB era. Having said all of that, if I had to choose 1 QB in a Draft it would be Peyton because he can win with any Coach as proven.