Actually I’m very fine with this one; I believe that you can have Good without having an opposing Evil, and it’s specifically the classification of things as Evil which I have issues with.
My pick for the ultimate Good in superpowers would be any form of creation/transmutation/destruction which violates the Newtonian conservation of energy and matter. If you could create or destroy substances without necessarily destroying or creating other substances, then you could turn back the clock on entropy, which otherwise inevitably dooms this universe.
(Post 1000 is either this one or the next, woohoo!)
(EDIT: Actually it looks like Pydro got 1000. And unsurprisingly, his answer to this question is extremely reminiscent of my worst nightmare.)