The first movie was okay. Beyond that, the ratings fall, and the first one was not well rated (I think it's like a 6 on IMDb, which is like below average).
I've played a bit of the original game. I remember I got to a school (or maybe a hospital?) and there's a scene where the world transitions. You're in another place all of a sudden, and what was creepy before, with weird stuff lurking around every corner, is now straight up terror, with things actually trying to kill you. That was about as far as I got. Maybe I rented it and had to return it?
Pyramid Head is an awesome (looking) villain but IIRC he doesn't show up until the second game?
I remember Silent Hill trying to be a scarier Resident Evil, or at least that was my impression of the games. And Resident Evil games were usually better. I liked the first three, beat all of them on the PS1 back in the day. If the fourth one was Code Veronica, I played a bit of that, but never finished it. I didn't play others. I think there was a demo of Village on Xbox I played later.
I should mention horror doesn't affect me the way it does other people. My interest in Silent Hill was the story, finding the guy's kid. With Resident Evil, it was the puzzles. So that creepy shit out the corner of your eye? I'm gonna go look at it. I can't recall a game ever scaring me.