I always catch myself thinking about how raw Texas chain massacre (1974, the original) was, it's my favorite horror movie, the dinner scene is so unsettling, it's a timeless horror movie.
I'm a sucker for Giallo movies, Dario Argento's movies are amazing, my favorite is Profondo Rosso.
Honorable mention to Noroi, Jhorrors are really cool, last year i was on a Jhorror bind, but Noroi was the one that stood out from the ones i watched. The pacing is really on point, it's a long ass film but it works, probably the best found footage horror movie i've ever watched.