I think they are a lot of good options, I think they have to be big enough to guard centers and quick enough to guard wings, and I think that gives 3 clear best options.

My three are Kevin Garnett, Wilt Chamberlain, and Hakeem Olajuwon. My argument for all 3 of those players are that I trust them to get a shot off versus anyone, and that I think they have a realistic chance to beat a MJ (can stick on the perimeter well enough, can bully in the paint) and Shaq (too quick on the perimeter, won't get destroyed down low)

Who ya got?