Alright I can think of a few that strangely haven't been mentioned yet!

• Barbarian - Woman checks in to an AirBnB. But beneath it lies a horrible secret. This one's pretty disturbing in subject matter, actually. But it's solidly eery.

• Tremors - It's bright daylight! In a small desert town! What's so spooky about that? Vibration-sensitive, man-eating sandworms maybe. This movie is just solidly fun all around. Legendary B-movie monster film.

• The Descent - Always thought caves were creepy? Want to experience claustrophobia from the safety of your own home? Wanna see how an all-woman horror film cast is done correctly? This one's a treat.

• Dog Soldiers - The Scottish Highlands are gorgeous for a hike. Less appealing though if you're a squad of British soldiers doing a training exercise in a monster movie. Features reasonably smart cast of soldiers doing their best, but cleverly using the training scenario premise to take away their live ammo so they can't just shoot away their problems. Also, I remember it being very "B movie" in a good way. A well-placed cheesy joke or two had me laughing out loud without it being Marvel-grade snark, but it was still tense and exciting.

• Pandorum - Guy wakes up from hypersleep on a giant ship where things have gone horribly wrong. His only other awake crewmate is uh...a bit off, maybe? This one feels VERY Deadspace. If you like "Creepy massive cathedral-like dungeon ships" flavored sci-fi horror, this one's pretty good. I'd say maybe much tamer than Event Horizon, but clearly took some inspiration there.

• 30 Days of Night - You know how in Alaska they get really long periods where the sun is just gone? You know how certain classic horror antagonists hate sunlight? Uh oh.

• Overlord - A World War 2 horror film. I mean, WWII was full of horror but...like... unbelievable horror. No, like, pulpy mad scientist supervillains and secret experiments horror--No, like stuff that DIDN'T actually happen. It's the closest to a Wolfenstein movie as we're gonna get. (And very "Weird Wars 2" if you've played a good Savage Worlds TTRPG or two)

• Resident Evil - I liked maybe two or three sequels too, before it got utterly ridiculous to farm cash, but the original is always cited as a horror classic, even among people who aren't fans of the games. (Almost entirely unrelated characters and plot.)