In terms of traditional horror-y horror movies, I 100% have watched Trick 'r Treat every year since it came out!
Other than that one constant, I usually have a rotating cast of horror movies I put on repeat (not going to lie, usually dictated by the HHN lineup, haha), including but not limited to: Slither, Shawn of the Dead, Sinister, Insidious I&II, Saw (really the OG, but the first three make a nice trilogy; complicated feelings on the rest), Dead Silence, Sleepy Hollow, and An American Werewolf in London!
For some lighter, family friendly fare I usually also have to watch Beetlejuice (I know it has an F-bomb, sue me), Hocus Pocus, and/or Ghostbusters!
I know these tend to be pretty mainstream in terms of horror, so one sliiiightly more obscure recommendation is actually a cartoon mini-series called Over the Garden Wall. It just OOZES fall vibes, and it is beautiful to look at (think Gravity Falls meets American Folk Art). It is just the right amount of silly and whimsical, and the soundtrack is sublime! The voice talent includes Elijah Wood, Christopher Lloyd, and guest voice appearances by Tim Curry, John Cleese, and Thomas Lennon! It has definitely gained a cult following over the years, and each episode is only 15 minutes long, so put together end to end it actually fills a movie time slot perfectly!