Most people (younger majority) ramble about how they'd be evil. Of course, most people only say this for the same reason they choose a black object over a white object. It's hard to say, but maybe the horrid Ninja obsession in America, and Star Wars, where the evil side is always awesome and the good side is always unbearably rainbow sunshine and flowers.
That sort of depiction is ignorant and cliche, of course, but I'd find it would make up the majority of decisions about this sort of thing.
It all depends on which way you look at it.
The Good Side Superman, Spiderman, Justice League, the works. These guys go out into the crowded streets and help people. However, these are stories, and things that would normally happen wouldn't.
You have to worry about Global Warming and Superman's Ice Cave. Planes when you're flying. The press. Media. Paparazzi. A better depection of what being a Superhero would be about is Spiderman, where it interferes with near every aspect of his life and threatens all of those around him. When you're evil, you can just kill everything and not care, but then you have a horde of Superhero's (i,e Justice League) who trail your ass all about space.
The Good Side is probably not the best choice when given consideration.
The Bad Side
This is for people who like to abuse their powers. The "Bad Side" people usually think of in these cases are more so "not helping people" as opposed to "going out of your way to slaughter millions of people". Wheather people actually have these guts are pretty rare, especially when villians lose in reality just as much as they do in the comics.
This is the side I would take. You aren't good, you aren't bad. You simply show off your powers and be the talk of the town, or keep them to yourself.
If you choose the bad side, you have to worry about the good side, and if you choose the good side, you have to worry about the bad side. But if you choose neutral, you can just sit back and enjoy the ability to lift cars and through them across football fields.