Psycho and Play Misty For Me are good for suspense.
A more recent, highly suspenseful movie is The Ruins. This had me on the edge of my seat.
Mrs G and I just watched a Thai movie called Shutter on Netflix streaming. A very creepy revenge-ghost movie similar to Ju On (the Grudge) or Ringu (the Ring). Highly recommended 
Divorced, he complains about paying alimony which is why they are screwing around and not married themselves. Marion comments she would rather be married and live in the back room of his shop [IIRC Sam said something about her licking the stamps on the alimony checks.]
Just checked IMDB, Marion said she would lick the stamps.
Sorry, I’m making two subtitled recommendations, because they’re scarier than anything I’ve seen listed here so far with the exception of “The Ring.”
The first is the Spanish film “The Orphanage.” The second is the Korean “A Tale of Two Sisters.” Both of these films are extremely, extremely scary and do not involve blood and gore. At the heart of both films is a theme of family secrets and tragedy that give them depth that you don’t often find in the horror genre.
Oh yeah, just remembered. It wasn’t as good as the hype but The Strangers is still pretty good.
Just ignore the “based on real events” stuff. Apparently in real life a couple went missing, never to be seen or heard from again. That’s the sum total of the “real life” on which it’s based. The story of the missing couple came to the attention of the filmmaker as a kid, and he always imagined what happened to them. This is his vision of that. So (obviously) there’s not one shred of real-life detail in the film; the entire story is made up out of whole cloth. Just an FYI.
I saw The Orphanage, and it was good. I will have to check around for the other one.
I saw part of an interesting movie, I will have to ask my brother what it was but it involved a very disturbed girl making dolls. Eve or something like that 
I wanted to borrow it to watch all of it but the part I saw was very creepy.
There is another movie that is interesting, The Gathering. Not overmuch gore but some good psychological suspense. I like the old house the family lives in [that used to be some sort of orphanage/boarding school]
I vote for whatever genre of horror is the closest to your vision of reality. What I mean is, when I was Catholic I was scared shitless by The Exorcist and the Emily Rose movie. Now that I’m atheist, I get scared by movies like Kierkegaard’s The Sickness Unto Death and Nietzsche’s Uberzombie.
We watched that a few Wednesdays ago. The girl I mentioned screamed so loud I thought someone was going to call the cops.
Another vote for** Session 9**. I have it in my Netflix queue to watch again, but I’m a little scared to!
I also agree with The Descent and Dog Soldiers.
**Severance **is a hidden gem - it’s horrifying and scary and brutal, and yet also has some fun winking at horror movie conventions. And yet no one has ever heard of it.
**Slither **is a lot of fun. More silly and gross, but very entertaining.
One of my favorites has to be The Others. Nicole Kidman as a widowed mother in a creepy house with two creepy kids and creepy servants. Then the weird stuff starts to happen.
Tense and suspenseful throughout with zero gore. It’ll make you shiver and your heart drop.
Yeah, The Others was pretty good. Fair warning that it moves very slowly and is all about the mood. As long as you don’t totally hate slow-moving mood pieces, it’s worth the time.
Well, if you don’t mind blood and gore, then definitely check out Inside, a French horror film. Plot: a lone, pregnant woman, scheduled to deliver the following day, is tormented in her home by a strange woman who wants her baby. Quite intense.