System Shock 2. Resident Evil. Eternal Darkness. The number of games that really get the unease that horror is supposed to deliver right is small, but one larger now. Amnesia definitely belongs on that list. Other reviews go better into the story and gameplay than I can, because of the one (admittedly subjective) shortcoming of the game: the effects the game uses to indicate Daniel's dwindling sanity feel like someone went crazy with the Photoshop filters menu. It started out creepy, but culminated in a case of motion sickness that, sadly, kept me from going any further in the game.
A very enjoyable Hack'n'Slash, marred by mechanical problems. The characters are horribly imbalanced, owing largely to very persnickety hit detection, rendering the physical classes problematic, and the fact that once you have the Dark Staff, there are very few cases where using the casters isn't the far better choice. This leads to some massive difficulty spikes at points where the levels were almost certainly designed for the "tank" classes (a certain level where magic punches right through shields/armor, leading one to the conclusion that you need the extra health to get through) except that they can't seem to hit anything. Still, as I said, it's an enjoyable game, if a bit of a throwback to the old "Nintendo Hard" days of having to play a level multiple times until you get the gist of it, actually adding to my enjoyment.