It goes:
1. 28 Days Later
Not just my favorite horror movie, but my favorite movie general. The atmosphere, the soundtrack, the subtext that keeps peeling like layers of an onion leaching viral toxins that will turn you into a psycho berserker in seconds flat- mmm, chef's kiss. Best horror movie of all time.
2. The Thing
One of the few films that gets cosmic horror right. Plus, it doesn't rely on the characters being dumb to make the monster scary- it's just that cosmically horrifying as an antagonist. Said monster has some amazing SFX, too.
3. Ginger Snaps 2: Unleashed
I like Ginger Snaps a lot. It's hilarious (Ginger and Bridgette totally sound like Rick and Morty- for instance, "If you don't like your ideas, Bridgette, then stop having them.") and actually scary. The sequel even moreso- I love the Excruciating Death rant that Bridgette goes on during group therapy, and the sequel has better SFX so that the werewolves don't look terrible, and having spent time in a mental hospital myself, I can tell you that it has the best portrayal of a modern mental hospital I've seen in media. Unfortunately. Plus, it heavily inspired Machine Girl's first album, which is great.
4. Videodrome
Embrace the new flesh. I mean, what could be better than a schizoid body horror movie by David Cronenberg where an anomalous TV signal gives out free cybernetic implants like a slit in your chest to hide your gun and is government approved by the CIA? Embrace the new flesh.
5. Rabid
Another David Cronenberg movie that proves fast zombies have been a part of that sub-genre for a very long time. Basically plays like 28 Days Later if it were made in Seventies and set in Quebec, and is also somewhat gorier than 28 Days Later. It's a bit slow to start, but it really pays off in the end.
6. The Cabin In The Woods
This movie is like a cosmic horror monster jamboree, overseen by a shadowy secret society. It's the closest thing I can think of to an SCP movie. It's also really funny and contains a blink-and-you'll-miss-it reference to Left 4 Dead in the form of the special infected turning up in the containment cubes.
7. Velvet Buzzsaw
So you know that trope in horror movies of an accursed painting that haunts the hell out of anyone who is in possession of it for too long? This movie does that right. The ending is really great too.
8. American Psycho
This movie was considered to be unfilmable by the books author. It's not. It is filled with biting satire, a soundtrack consisting of all the bangers from the '80s and a main character so cold you feel the black hole in the earth he feeds his victims to trying to swallow you up.
9. Invasion Of The Body Santchers (1978 version)
The best version of the paranoiac classic. The fact that it's set in NYC in the Seventies just makes it that much more plausible that people would be ignorant of the martian fungoid plot to replace humanity. NY was more crazy than the rest of America back then, which is saying a lot when it's the decade that had more crime than any other time prior in America and the closest thing to a domestic insurgency in US history that I can think of. Of course people would think Donald Sutherland was crazy and wonder what kind of psychedelics he was on in that time in place, especially when you consider how little people at the time even paid attention to groups like Weatherman and the massive amount of bombs going off in the city at the time.
10. Overlord
It's the closest thing to Wolfenstein: The Movie I can think of. GET PSYCHED and go watch it.