The Fog
I love this film. Watch it like I do, with a smoke machine on. This has everything I love about older horror movies. Ghostly back story, pre-CGI effects, and I love that the undead sailors are seen but unseen. Carpenter is great at creating an atmosphere. And the synth heavy score adds to the tension wonderfully.
Begotten
If you have the time, or for some the patience, this is worth sitting through start to finish. Obviously not a particularly clear narrative, and with no dialogue or discernible music, it is still immensely bleak and horrifying. This is often on in the back ground in the studio, and coincidentally was being played on a projector.