Okay I know they were already mentioned, but I just wanna say I also love these:
Hocus Pocus
The Nightmare Before Christmas
The Rocky Horror Picture Show
Not necessarily set on Halloween but still movies I love during the season:
Practical Magic (this is my absolute favorite and I watch it every year)
The Craft
Coraline
Beetlejuice
Army of Darkness
The Others
And then not a movie but a youtube series: Marble Hornets
Edit: If you're looking for movies I consider spooky, then: Wes Craven's They, The Others, Haunting in Connecticut, The Woman in Black, It Follows was weirdly creepy, and yeah if you like found footage stuff then definitely check out Marble Hornets. If you like psychological horror, A Tale of Two Sisters is great.