Outlast--Holy fuck this game has some intense moments. Jump scares are the lowest form of horror, but "Outlast" probably does jump scares better than any game I've ever encountered. Plus, it's probably the darkest game I've ever played. And I mean "dark" literally as probably 85% of all levels are pitch black. Which means you can only view them via night vision camera which gives the whole game a creepy "Blair Witch/Paris Hilton Sex tape" vibe.
That said, it has its flaws. Chief among them being that it's very trial and error. Alot of the game consists of almost "Mirror's Edge" type sequences where you have to run from pursuers. More than a few times I found myself suddenly in a very intense sequence where I had to search for some component to proceed, only to die and have to restart. After the 5th time of doing this, all fear turns to straight up tedium and frustration as you fumble around in the dark searching for the right components, being killed repeatedly, until you finally stumble on them seemingly at random. Which completely deflates any tension the game had built up to that point. Plus, as with "Amnesia" (which was also very intense in its opening segments, but less so as it progressed), eventually you learn how to "game" the monsters and their mystique wears off, making things much less scary. But to its credit, "Outlast" has more than a few twists and tricks up its sleeve to keep things varied (the best being suddenly throwing you outside in one sequence, which is incredibly eerie and hard to navigate via night vision as you can only see a couple ghostly feet in front of you). Plus, it's shorter than Amnesia (only like 4 hours) so it doesn't wear out its welcome.
Anyhow, it's games like this which makes me fear/covet VR. Playing this in a VR helmet would be potentially traumatic, I think.