I think it would depend on what super-powers I had.
Superman: Hero. Why not? Besides, it would tear at the heart-strings to hear EVERY CRY FOR HELP ON THE WHOLE PLANET.
Spiderman: Showman. I'd do crazy stunts and crap and attribute it all to some Christ Angel bullshit. Rake in the cash. What? Spiders can't stop bullets with their face, so I'm not going to try.
Batman/Ironman: I'd be rich and wouldn't care. After all, money is their super-power.
Hulk: Smash?
Blue Beetle: I'd take over the Reach. Hells yeah. Actually, more realistically, I wouldn't have the will-power to overthrow the Reach's control, or the luck to have that stuff with whats his face the bounty hunter looking guy happen that would have made their control less effective, so I'd take over the planet in the name of the Reach.
Green Lantern: I wouldn't have a choice. I'd be a Green Lantern. Although I doubt I'd have the will-power necessary to attract a green ring. A blue or red one maybe, but not green.
Mega Man Bio-Metal (Preferrably one designed after Blues): I'd actually probably go to the government at that point and say, "Hey, I'll end that war for you."