I'm not too big of a fan of Silent Hill. The first game was pretty cool when it came out, due to the refreshing emphasis on the supernatural rather than science. I absolutely hate the second game, though. When my sisters and I played it, we got this ending that was so ambiguous and unsatisfying that we decided never to play the game again. The third one was a bit better; I liked the intro area with all the wierd cadavers in bunny cosutmes. I haven't played SH4, but it looks kind of crappy compared to the fourth Resident Evil.
I think my main problem with Silent Hill is all the fucking endings. I like games where the final outcome isn't determined by every minute decision you make. That was the reason I hated Resident Evil '3'; there were too many damned endings that were influenced by too many damned subevents. That's pretty much how every Silent Hill is.