I think Penumbra looks scarier myself. Something about always seeing that pale alien right on your tale just scares the crap out of me. Yeah things like Silent Hill I have gained a tolerance for. Nice to see a fresh horror game. If you have Half Life 2, there is a free mod called Nightmare House 2 that is also really good. Here is a video of that. It is also the same guys freaking out as the previous videos.
http://www.youtube.com/watch?v=bj0nKviflug