Among the many to choose from, the one that would allow me the most anonymity with the most gains would have to be Prof Xs mental abilities. OOH!! No! Better than that, there was an X-Files episode about a guy would could impose his will on others simply by suggesting things to him ("cerulian blue" anyone?), I would do that. Be like, "Hey Superman! Bench press that volcano!" and he'd be like all "oh no! I can't stop myself from bench pressing that volcano!" And I'd be all like, "You are powerless against my will!" And then the whole Justice League would jump out and be all like, "Oh no you don't!" and i'd be like, oh yes i do! And then i'd tell them to slap each other in the face until i said stop, and then they'd do it?
or flying...
That'd be cool....