The music in Silent Hill is definately an important part of the experience. I dont think I would enjoy that series as much without it.

Im most fond of SH1 and SH2's soundtrack. The ambient music works well with the atmosphere and tone of the games. SH3's was good but other than the main theme, it wasnt very special. SH4's was a complete let down, I cant even recall a single tune from the game, just none of them stuck out. SHO's was surprisingly good, and much better than SH3's and SH4's. I dont know if it is as good as SH1 and SH2 but its up there and definately the best thing going for that game.