I have read all of the d20 supers variants thus far, the horrible Foundation, the Godlike d20 conversion, Vigilance, Paragon d20 and the preview of the Natural version is Asgard. In almost every way, the Paragon d20 version is, IMHO, the way to go. I plan on adding a few things that I did like from the other rpgs to Paragon, but over all I think Paragon beats them all!
Still, gotta see Mutants and Masterminds. Green Ronin is a great company and they may be able to one-up Paragon. Remains to be seen.