I'd still take Benzema over Higuain. Sorry Deneb. I'm with Cheese on the Higuain vs Benz comparison; one is the better scorer (although Karim is becoming better and more consistent), whereas the other is the more complete footballer.
As for Riquelme vs Xavi, Riquelme is a footballing genius. It's rather unfortunate he was unable to express his full potential in Europe. Xavi is also an extremely talented footballer, so claiming that one is far superior to the other, or shits all over him, is rather immature and silly. Both are extremely talented footballers with exceptional abilities. One was quite unfortunate given the circumstances and coaches who played him out of position/didn't believe in him, while the other is able to express himself to his full potential/ability in a setup very much suited to his game.
Gaitan is an amazing talent Cheese; he's valued at 30 Million Euros by his club, and is tracked/wanted by clubs like City and Melo's United

He will have a stellar career.
Oh, and for the record, Taarabt shouldn't even be mentioned in the same sentence with Balotelli. One has the potential to be World Class, while the other is going straight to the footballing trash can