Horror-themed games from the past

Sometimes I like to spend quite some time looking at Google Analytics statistics of Abandonware DOS. I'm amused that "horror" (and variants) is a much searched keyword.

What is that you like in horror games of the past? Did they scare you? I remember that the game that scared me the most was Doom (I played in the dark with headphones and I'm sure I wasn't the only one), something a bit different from a "horror game".

Anyway, since you like them, here are some horror-themed games for you. I doubt that they're scary enough, though.

rpg - 1989 Don't Go Alone

adventure - 1993 Jack in the Dark

adventure - 1989 Personal Nightmare

rpg - 1989 Vampyr: Talisman of Invocation

action - 1993 Endless Horror

adventure - 1990 Hugo's House of Horrors