Jackson
Mills / Davis
Swilling
Johnson
Vilma
etc
Honestly, I think you could possibly make the argument for being #2 behind only Jackson just due to the different nature of the game today. He has to play both the run and the pass, and while there was passing back in the Dome Patrol days, every team didn't have an opposing RB or TE that they featured in the passing game. And definitely not taking anything away from Sam, but I don't think his responsibilities were what Davis' are today. And Davis does both well in an era where it's demanded of the position.