Is there anyone out there now who doesn't think Messi is the best they've seen? Or even the best in the world?
Xavi and Zidane IMO.
I equate 'best' with controlling games though. Also, I don't think the 'international stage' argument is as spurious as everyone would have you believe. Comparing him to the likes of George Best is facile IMO.
Some of his international colleagues currently include Aguero, Higuain, Tevez, Mascherano, di Maria and many other top class players. Don't even get me started on the likes of Colo and Gutierrez
I don't personally believe he is incapable of performing outside of Barcelona, but if he really wants to compete with the ilk of Maradona, Pele and other candidates, what is stopping him from doing the business at the
Grandest Stage of Them All,... Wrestlemania!
[And I ask that as a very sincere question].
The respective abilities of players are not characterised by success at a single tournament type, they are what they are - inalienable almost, but given Messi's supreme talent, he should be able to replicate his form at a World Cup. I suppose it depends on how you see 'greatness'. Do you have to do great things to be great? Or can you be great without ever fulfilling your maximum potential?
He will be great no matter what now, but if he wants to contest for the title of the greatest - he still has challenges ahead of him. He's got youth on his side, and I hope he does perform at a WC like he is capable of doing.