What other scary games are there? (for PC)

[SquigPie]

Cryostasis: Sleep of Reason (Weirdest game you'll ever play, also unique and very philosophical, not to mention piss scary)
Condemned: Criminal Origins (Gritty and rather realistic, also holds many famous scares)
Penumbra Series (obviously)
Dark Fall: Lost Souls (puzzles where made by someone who'd done too many drugs, and plot went out the window towards the ending. But scary as shit point n' click game nontheless)
System Shock 2 (Outdated in some parts, and some of the intended scares I found hilarious, but creepy as shit and memorable plot)

Mods:
Nightmare House 2 (Great horror mod, not without it's problems, but fantastic nontheless)
Afraid of Monsters: Director's Cut (AI is retarded, but amazing mod and very scary.