I still prefer to watch Horror movies from the 70s/80s. Sure, the special effects are laughable now, but they actually build a tense, suspenseful film experience. The original Amityville Horror is probably my favorite horror film, followed by a tie between The Exorcist and Halloween.
I was enjoying the Halloween remake until I got close to the end, where Michael Myers seems to care about his sister. Umm, no, the only thing he cares about is shoving his knife into her heart.
I didn't really like them showing his time spent in the asylum as a kid either, but that at least made him out to be a psychopath incapable of love. Also, the whole "I'm inhumanly strong" thing was hard to take. No, sorry, I don't believe he just ripped apart that chain...
But yeah, modern horror movies largely suck. It's like they've forgotten the importance of getting the audience tense and fearful merely by ambiance. And that's really important, imo, to making a horror movie actually scary. Just making things jumpy/bloody? Nah.
Alien was pretty good too, but is really different from the rest. They make use of making you jump more than the rest, but they never do it solely for the sake of making you jump. They actually played with you in that movie, by creating many moments where you suspect something to jump out where nothing happens. It made the actual moments more tense, imo.