Who is the best rugby player in the world?

Question

So, just who is the finest rugby player in the world today?

Richie McCaw was named the International Player of the Year at the end of last year, but he faced stiff competition from Brian O'Driscoll and Fourie du Preez. Meanwhile, Dan Carter and Brian Habana are widely recognised as two of the finest players the sport has to offer.

But who is the best?