I dunno, it looked pretty dull when I saw it some 15 years ago, and from what wikipedia has to say, it sounds like its actually managed to go downhill since then. But on the otherhand, if you want to squat Silent Hill, I doubt anyone's likely to put much energy into evicting you, as long as you're persistant.
If you do visit/squat, just remember that most of that land is eventually going to fall into the collapsing, flaming mines; so it's probably best to stay away from the places that are thin enough to vent smoke/steam.