It depends on the superpowers I have, I guess.
If it was just flight I'd be responsible, and cut down on emissions by just flying everywhere and not having to use a car. I'd even give other travelers a lift (no fatties).
If it was lightning I guess it'd depend on the situation. I could use lightning to do good things like taking down criminals or healing the sick and injured (electricity is like medicine, right?)
But if it was like shapeshifting I think I'd probably be more of a jackass, since I could protect my own identity by being in something else's form. Like I'd transform into a fire-breathing dragon and pay a visit to a local Catholic church (I wouldn't kill anyone, just would like to see their reactions), or into a T-rex in a museum of natural history (not so extinct now, huh?), or into a kangaroo and... ...file... sexual harassment suits in Australia? I didn't think that one through so much.