Hard to compare players from different eras. Ive been watching us for jsut over 40 years, cant put players in order, but the best for me would have to be:
GK: Schmeichel>VDS>DeGea
Full Backs: Irwin>Evra
CB: Ferdinand>Stam
CM: RObson>Keane>Scholes
Wingers: ROnaldo>Giggs>Beckham
Number 10s: Cantona>Rooney
Strikers: Ruud Van Nistlerooy>Yorke>Hughes
Not going over medals, time at club , purely ability and performances for us at the club. Could be loads of memorable mentions of coruse, but for me, these players stand out above the others, all players that could have played for any club in my opinion.
I think Beckham and especially Yorkes careers here are seriously under rated. Both were pure quality in terms or work rate, attitude, ability and production during there times here. I know Yorkes time here wasnt particularly long but his name pretty much never comes up amongst our best ever strikers its very often RVN or RVP. Hughes bit biased and sentimental on as growing up alongside Robson he was a hero, but still if not the best, one of the best I have seen at holdign the ball up