In terms of achievements, few can come close to Zizou... winning this World Cup would just cement that further.
In terms of all round ability, I believe he is in a league of his own. The best player to ever touch a football! He can do it all. Like I said before, he is an artist. When he is on the ball, it's poetry in motion... in his prime, he just made a fool of anyone who tried to challenge him.
He can header better than most, he has a beautiful first touch, he can pass the ball short or long distances off either foot with insane accuracy, same goes for shooting. He can control a game like no other... his vision is unrivalled... he is a great leader... a fantastic dribbler with a huge array of skills and perfect balance. Probably most importantly though, he always rises to the occasion.
You couldn't ask for anymore! The perfect footballer.
Whether he wins the world cup or not wont make any difference to what he has achieved before and it certainly wont erase all of his unbelievable performances down through the years. He is the best, with or without this World Cup.