Scary movies that have stayed with me over the years do so for a reason - they build tension, and leave a whole lot of stuff entirely to your own imagination. Over-reliance on special effects and herky-jerky first person camera action have diluted the genre.
There are more than these, but these are the ones that come to mind without a lot of thought.
Jaws
The Thing (Carpenter)
Alien
Night of the Living Dead (original)
Carrie (original)
The Shining (original)
The Exorcist
The Descent [more gory than the others...it's the tension between the "friends" that makes it memorable, not the action]
The Birds [This one is kind of hokey by today's standards, but the first time I saw it, my parents & sisters were out for the evening; I was home alone (I was about 12 at the time). When my family came home, I was huddled in a blanket in the family room, clutching Bessie (my stuffed dog I've had since birth). When the starlings flock on campus in the evenings, it's VERY unnerving to me still!]
Impressed that you refer to The Thing as "Carpenter" instead of "original." Most people think that one was the original.