Gabriel Knight/Nightmare Fuel

The High Octane Nightmare Fuel page for Gabriel Knight.

The first Gabriel Knight was plenty creepy in general (or at least until the mummy zombies started showing up), but the part where you are talking to a poor junky in a church pew who proceeds to STRANGLE AND DIE right in front of you for no reason you can see while the soothing organ music plays softly in the background... STILL gives this troper chills, even a decade later. It's not made any better by having to search his corpse and copy down the tattoo on his chest. Again, WITH the organ playing peacefully in the background.
- So that's the one point I didn't get! I wonder how it's possible to miss that.
Anyhow, how can you just gloss over the zombie mummy sequence? Five game-days into the story (which up till now has been a present-day realistic mystery game, with no threat of on-screen death) and you are suddenly assaulted by face-tearing mummies - which you have no weapons against - and must drag-ass away from at half the speed of the mummies themselves. -click- It works! "Uh-oh. I think something just happened." (bodies in the corner of the room untangle themselves...) Like a literal waking nightmare.
And then Gabriel's uncle reaches in his own chest and rips off his own heart. Yes, it's Fridge Narm, but sheesh.
At one point in the game (prior to the scene with the junkie) you find yourself in the park, where you come across a fortune teller you spoke to earlier in the game and inadvertently scared off when she read your palm. When you talk to her, she suddenly becomes possessed by Tetelo, who warns you to stay away from Malia Gedde or pay with your life. Frikkin'. Creepy.
When you're in the voodoo cabal's headquarters, everything is very clean and orderly, like any other building. Then... there's Dr. John's room. Suffice to say, it's not as tidy.
Then there's the cave in the second game.