I prefer older, classic horror films too. Here's a list of films I recommend.
Note: some of these movies have remakes. I am not recommending those.
"The Haunting" - obviously a classic, the best "haunted house" movie ever IMO
"Village of the Damned" - one of my favorites, great scifi-flavored horror
"Kwaidan" - a Japanese anthology of ghost stories, all of which are excellent
"The Wolf Man" - My favorite of the Universal classics
"Kiss of the Vampire" - of the famous Hammer studios, my favorite of their horror line
"Carnival of Souls" - a very low-key movie, atmospheric and spooky
"Fall of the House of Usher" - I like the Roger Corman/Edgar Allen Poe/Vincent Price films from the '60s, and this one is the best
"Ghost Cat Mansion" - this one, admittedly, isn't going to be easy to find, but I love it so much I had to mention it. A great ghostly revenge story set in pre-modern Japan.
"Salem’s Lot" - Stephen King apparently hates this television adaptation of his famous novel, but I thought it was especially well done
"1408" - I wanted to list at least one recent film, and I did like this one a lot.