Most people on here know my opinion of Beckham. The legend debate will rage forever. It still rages about Ronaldo & Keane..and to some even Schmiechel. No one will ever fully agree on a conclusive list beyond the mainstays of the Holy Trinity, Edwards, Scholes, Giggs & Robson (and I fear the younger generation may sadly forget him, for reasons stated below)
Personally I think that whole '99 Midfield are legends. The greatest midfield we've ever had and his contribution to that season alone would be worthy enough of the status at any other club. People often say odd things like he never did it on the very biggest stage, but as a winger, I'd say setting up both goals in the CL final is about as good a contribution on the biggest stage as you could hope for.
We've won the European Cup 3 times, and aside from Cantona & Edwards (who most consider would've won it) the top players from those seasons are the ones remembered as legends accordingly, with their contribution to it elevating them beyond the plethora of great longstanding loyal players (Robson aside, none of our star players from the less successful years are given such reverence) And as weird as it may sound now, if it weren't for Giggsy's yoga induced indian summer the question of who was better wouldn't be such a straight forward one. Of those hallowed 4 he was the least effectual of that year. The Arsenal goal was iconic & legendary in itself, but it was the other 3, Keane & Beckham in particular, who were the true performers of that term, and the ones who propelled us to it. And lets not forget that Becks also scored a cracker in that very game!
The whole media whore thing is offset by the opinion of him within football. He's been a hit with the fans of 3 of the biggest (if not THE 3 biggest) and thus demanding clubs in the world and is widely revered as a great player & professional from those who played the game. Those who want to downplay his contribution are welcome to, but they're outnumbered, and he'll go down as an icon of the sport (the actual SPORT) regardless.
In that regard at the very least, wherever the legend ball falls, I'm proud that possibly the most famous face in football was not just a United player, but a passionate one, who's biggest legacy will have been created and remembered for being here.