Amnesia: The Dark Descent or Penumbra: The Black Plague?

[Googolplex]

There are spots in each game where I'd get stuck on a puzzle or at a sequence where I'd die over and over. Definitely an immersion killer.

That improved the immersion for me.

I do like Penumbra's story just a bit more though. The ending to Black Plague was amazing.

The ending of Black Plague was bad. I know, it should be something "intellectual", but it was strange and not really credible like it felt in Overture.