For me its got to be MJ. I am obviously bias on this one but the things MJ could do on the bball court were simply amazing. If he hadnt left for 2 years I am 99% sure the Bulls would have won 8 straight titles. He did all of this without ever having a dominant center. Besides the Bulls who was the last team to win an NBA Championship without a real good low post big man? I think that explains enough.