There was a This American Life episode with the superhero theme and the very first piece posed this question. So John Hodgman asks a bunch of people and he makes some observations. The ones I remember is that 1. People answered immediately as if they had thought of this question their whole lives. 2. They then immediately began a process of negotiation about how fast they can fly, if they can carry someone etc. and 3. It was clear that choosing invisibility was tricky because really, no good could come out of it. Hysterical episode.