I know im not that old and o never saw the purple people eaters or fran tarkenton play, but AD is quickly becoming one of the greatest of all time not only for this franchise but the nfl. He's already top 20 yardage wise in only 7 years!
Bobby Wade, hands down
No matter how things ended there is no other player who has ever been a Viking that singlehandedly changed the game and the way teams prepared for us like Moss did.
That being said if I were to pick the player who was the best at his position for a long time as well as a positive for the community I would throw the name Randall McDaniel into the mix.