This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / No More Heroes
When trying to get the location of the #5 assassin from Sylvia, Travis loses the connection and is left on his own. So how do you find out where to go? Well, you could either look at the minimap like usual or follow the freaking trail of blood that suddenly appears out of nowhere.
And then you get to the end of the blood trail. There's a murdered woman's body lying in front of the spot. You never find out who she is, who killed her, or why. She's just there.Even though you don't actually fight Letz Shake it makes the atmosphere a lot chillier than before.
The cutscene and fight for the #2 assassin, Bad Girl. Of course, most of the game's schtick is switching between lighthearted parody and Nightmare Fuel moments.
There's also the time that the #4 assassin gets his eye sliced off, cries because he's scared of the dark, and his "assistants" tie him to a crucifix and cut him in half with a giant circular saw blade. And everyone starts applauding, despite the fact that no one is in there.
The Sequel ramps it up about 13 notches. Matt Helms... A distorted Uncanny Valley baby face mask stuck in the most horrifying innocent smile on top of a fat as shit body carrying a flamethrower battleaxe and the most chilling childlike laugh. Like Pyramid Head dressed up as Hello Kitty. That laughter will forever haunt your dreams. Not to mention the entire stage building up to his battle slowly gets darker until you're at Camp Crystal Lake: Silent Hill branch.
The housing complex where you fight Alice can be a little creepy if you look at it certain ways. It's basically a New York-looking apartment complex, but there's no music for most of it just a creepy wind. Then you enter the dark, run-down apartment building with broken down hallways and eerie inaccessible areas that trail off into pitch blackness. Then the last leg has an unusually serene, lost-sounding music.
And when you finally get to fight Alice, there's the battle theme (starts at 4:19), where a good chunk of the piece is accompanied by an ominous sounding synthesizer.