And everyone seems to take offence if you debate their opinion. :O
Steve, you say the best stamp their mark on their team, make their average/good team mates look good. But who does that more than Messi? Messi is a genius, who simply transcends all previous footballing styles. Xavi, while extremely good, is confined to the safety of doing what others have done throughout history, albeit almost perfectly. If I were to compare this to guitarists, Xavi is like Eric Clapton, who can play the blues perfectly, like no other does; but while he's confined to the limits of a guitar, Hendrix took those limits and re-defined what the guitar could do - and that's why he'll always be considered the greatest ever. You look at Messi, it's not the records he's breaking, it's HOW he's breaking them. He constantly produces moments of magic that others would have deemed impossible with a football, he's a genius who looks like he can do what he likes with the ball. He can win a game, all by himself, how many others can do that? If the rest of his team are playing poorly, all it takes is one of those unstoppable drives into the box that are nigh on impossible to stop, and he scores. If that's not making average/good players look good, I don't know what is. Is that not altering how his team plays?, stamping his mark on the game and his team? Xavi is performing a relatively simple role, he isn't altering how Barcelona play, he just happens to be one of the best ever within his role. Look at all the top teams around right now, all of them feature someone who can sit back and dictate the play for fun. Look at Leon Britton at Swansea, for instance. Xavi is phenomenal, but he's not a game changer, like your own criteria suggests he should be. Messi, however, is. He's the most unique and most magical player to come around in a **** of a long while.
And then Ronaldo, how many players in history have combined sheer physicality with technical ability like him? Strength, a tremendous leap and electric pace, an outstandingly good goalscorer with a great heading ability all rolled into one complete package.
All of the players you noted took the game, changed and did what they liked with it. Xavi, for me, doesn't really do that.