Michael Phelps, Wayne Gretzky, and Michael Jordan

These men are/will be the standard to which all others in the sport will be compared to for the foreseeable future. They are also both internationally recognized which adds to the fame.

I don't think Brady makes the cut, nor does Pele/Messi/Ronaldo. The fact that there is a discussion for who is the best tells me that none of them are that much better than the other. While they may be the best to ever play the game but Olympus was the home of the gods. Occasionally a mortal would beat a god in some competition, but the people who belong in the group should be embarrassing anyone who comes against them.