This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Resident Evil: Code: Veronica
There is one point where the player enters a small clinic. There are two gurneys, one with a dead zombie, the other with a body bag. Reading the journal on the table reveals that the doctor here was severely screwed up, and going into the back room, a freaking torture chamber, pretty much drives it home. But that's not the worst part. The worst part is when the player returns to the clinic room; the body bag is open, and the zombified doctor is now feeding on a corpse that was lying on the medical table. Not only does he attack you, the half-eaten corpse gets up and attacks too! Imagine what that would look like with today's more realistic graphics...
Returning to the clinic triggers a different transition screen, scored with a loudly thumping Heartbeat Soundtrack as Claire slowly, cautiously approaches the door and reaches for the doorknob. She knows something very bad is on the other side, and so does the player. This alternate sequence happens at a few other key points as well.
The Iron Maiden room. Going through a room filled with various torture devices? Check. Finding out there were sadistic people here to watch? Again, check. Reaching the end to find a room that rapidly fills with gas, forcing you to stop it via a statue, then sticking a rusty sword into the device, with a zombie inside suddenly popping out and biting your face? Check. One final caveat: Running out of the room doesn't mean you're safe. The zombie WILL follow you... And he's tough enough to eat multiple grenades before going down. The novels cover this in Claire being so freaked out she runs, regardless of ammo dropped getting out, no way off the island is worth it and dearly hoping the doctor behind it died a horrible death and went to hell.
Bandersnatches. Those things with one elastic arm. Yeah, they look a little goofy, but they have the talent of always appearing in the worst place at the worst time, and they're difficult to outrun because they can use that elastic arm to hookshot their way across the room and attack you.
The moments leading up to the first bandersnatch encounter. Alfred traps Claire in the corridor via a shutter, before going on the intercom to gloatingly inform her that he's set up a "special playground" just for her. When the player subsequently opens the door to the next room, the loading screen is horribly tense, showing the door opening incredibly slowly, with a heartbeat sound effect in the background. Cue Claire entering the room and... there's nothing there. Just a quiet, empty room, containing a couple of empty machine guns. Better collect them before going to get the ammo... OHGODWHATTHEHELLISTHATTHING.
Claire being trapped withSteve, who has been turned into a monster and now wants to kill her.
Wesker's return. Imagine your worst enemy not only coming back from the dead but doing so with super powers, which he uses to give you a no holds barred beatdown. But at least Chris knows what he's up against to some extent. Claire only barely knows about Wesker and he releases his inner asshole by beating her within an inch of her life. She lives only because he allows it and you know he's still watching her every move.
Everything about the Ashfords' private mansion, LEAST of all the zombies, bandersnatches, and goddamn bats. In the main room, the camera gives you unclear glimpses of a human like figure as you ascend flights of stairs. Only when you reach the top to you realize that it's a life-sized doll hanging from the ceiling. Alfred and Alexia's bedrooms are pretty creepy too as well as their "play room"