Besides Amnesia the only game that got unplayably scary for me for a while was Half-Life 2. There is a level where Freeman must cross a girder bridge, that level invoked a degree of acrophobia I haven't experienced in a game before. I got through it by deliberately jumping down a few times to get used to the idea of falling to my death. ;-)
Fortunately I'm not afraid of spiders, that could disqualify a lot of games.
Fortunately I'm not afraid of spiders, that could disqualify a lot of games.