1st we must qualify the term "Best Player". 

This does not imply the one with the sickest skills, but rather the best player.

Players are judged by wins and losses, so you have to take one from the back-to-back (O4's if you will).

Then you need to decide who made the biggest impact?

To me, that is hands down Joakim Noah. Al was an awesome big man. Brewer was probably the most talented. Green knew how to dish the ball... But Joakim is the one that unified them. Through his outspokenness, and his passion for things outside of the sport, he made this rag tag bunch of guys "best friends". In my heart, they all came back because Joakim did. He just won MVP award for the national title and was projected as a top 3 pick by some experts, yet he said that there were things that were more important than the NBA. Joakim led that team. He led his teammates. He led Donovan to a back to back National Title.