YESSS!! I LOVE AUTUMN!!!!!!! Thank you so much for this thread Jeepers Creepers is such a good start. The first one is a classic -- and the second is a guilty pleasure, because it's sooo fun to see everyone crammed into a bus, panicking.
Every year my SO and I are only allowed to watch horror movies all of October; we're five years running now. It turns us super weird by the end of the month, but I wouldn't have it any other way.
MOVIES
The Descent - A classic! Badass women in caves, claustrophobia is only the beginning of this chaotic tale
Sinister - A writer moves into a home with his family and finds some very unsettling tapes in the attic.
This movie is great if you want to be unsettled. Really top notch, creepy vibes. As a warning though; there are jump scares, but IMO they're not cheaply done, they're super effective
Cabin in the Woods - this one subverts horror tropes, which is really fun to watch. Comedic but also suspenseful
I also love Found Footage movies for some reasons, so a few recommends for those are (besides the obvious blair witch):
As Above So Below - I don't see this one recommended very often but it's such a favorite of mine, some indiana jones-style treasure hunters go into the Paris Catacombs where they believe the philosopher's stone lies. They go deeper and deeper...
V/H/S - an anthology film! lots of fun. The second one is good too if you enjoy the first.
[rec] - A reporter tags along with some fire fighters who are investigating an apartment building where some weird attacks are being reported! (not english; there's an english remake but it's not quite as good)
Grave Encounters - Ghost hunters lock themselves in an abandoned, supposedly haunted asylum.
Hell House LLC - A homemade haunted house attraction goes horribly wrong and years later a documentary team decides to return to the scene and figure out what happened.
TV
Anything Mike Flanagan (Hill House, Bly Manor, Midnight Mass.) Midnight Mass is probably my favorite, but it can be a bit monologue-y for some people (I LOVED the writing myself, great character show). Bly Manor is great if you want extra gay with your horror. Hill House is more classic horror rooted in family. All great tbh!
Into The Dark is a horror anthology series, every episode is basically a mini-movie!
American Horror Stories is a fun time too-- another anthology series, from the makers of American Horror Story, obviously
Channel Zero - Every season is a new story, based on popular internet Creepypastas! I'd recommend starting with season 2, which is based on the creepypasta NoEnd House
GAMES
Okay, I promise, i'm almost done. But I wanted to give a quick shoutout to Supermassive games, who make survival horror games you can play with friends to make an interactive movie night!
The most popular one was the first one, Until Dawn (I don't want to give away what kind of horror this is but it's a bunch of teens isolated in a cabin on the mountain). But they also have Man of Medan (nautical themed), Little Hope (witchcraft themes), House of Ashes (I... don't want to give this one away either, but it starts with a military group going underground) and, mostly recently, The Quarry (I haven't played this one yet, I think it's more classic slasher?)
The way it works is that you can assign everyone a character and you can pass the controller around and have that person be in charge of that character .... and try not to kill them!! Harder than it sounds, haha
I have way more but I must resist typing up a whole novel. i'm so excited to see everyone else's recommendations, and welcome to spooky season everyone!