I enjoy horror sort of as a concept and horror movies en made rather than a lot of discreet examples. It's sort of "here is a bunch of weird things people make movies about". It means even if an individual movie kinda sucks it is just one more data point.
If you want a weird suggestion of a range of them from good to trashy to interesting as things that exist?
I Spit on your Grave (warning this one is roooooouuugh), Last House on the Left remake (same) both cover off a weird side part of horror, both that reinforces but is kind of a response to Last Girl stuff. They are both Rape Revenge movies, which is hard to deal with.
Nightmare on Elm Street 1 & 3, both of these are 80s camp while playing with big concepts when paired together.
Valentine, a textbook post Scream suspense thrillers. Urban Legends sort of fits the same space but tries to be More Scream and fails.
Behind the Mask: The story of Leslie Vernon. Cabin in the woods hits similar notes, more serious though.
Sopko would slap me if I didn't say In the Mouth of Madness, I figure you have seen that though.
Oh and Event Horizon if you want Doom's plot ripped off and played completely straight. Some sexy Sam Neil action there.
J-Horror, K-Horror and Body Horror also have a bunch more there I either don't know or didn't note because it is too big and I don't do them justice. The body horror wiki has a damn good checklist to hit and honestly just ask Alex for recs. He doesn't compulsively consume it, but he knows good stuff.