I like the idea of it being around a highschool. It could be a small town, too which could be interesting, though I think it would limit the realisticality in the game (granted it's not totally important so...).
Although.... there was a town I'd looked up for a character of mine that might be good. It was in Granada Hills, Los Angeles, I think. Fairly average size, good place for a high-school oriented supernatural plot.