Navagon: Amnesia is kind of like a fully developed Penumbra. That said, Penumbra Black Plague has a lot of good things to be said for it.
Also, when you say non-shooter, are you ruling out all possible forms of combat?
By non-shooter, I mean basic shooting is out. For instance, Bioshock made me jump and gave me the creeps a lot. I really liked it. But after seeing some demos of Amnesia, I was opened up to this new-to-me style of game. I thought I'd give the best a shot.
With kids, I have little money and little time for games. But I thought a good scary one would be fun to pick up during a Christmas sale.
Right now, I'm feeling like maybe getting Amnesia first, then going through the Penumbras if I like it pretty good.
I remembered looking at Dark Fall and not liking much about it, but Scratches looked like it might be a bit intense.