That leaves The Invitation and Don't Breath as recommendations I'll consider. Thanks.
Thank you, too Phoenix87x. I've seen most movies from your list. Undeniable classics.
The ones, I believe, I havn't seen are: Phantasm, The Dead Zone, Manhunter and Black Swan.
Definitely see Don't Breathe and Black Swan. They are both awesome. Black Swan is more psychological and weird, whereas Don't Breathe is more intense and brutal, but they are both amazing in their own ways.
A Girl Walks Home Alone at Night is excellent, too. If you decide to check it out, do be prepared for subtitles, as it is filmed in Persian. So if that's an obstacle for you, you might skip it, but I highly recommend checking it out. A surprisingly fresh and stylish take on the vampire genre.
Speaking of vampires, if you haven't seen Let Me In, do. It's another vampire movie, but it's a uniquely emotional and atmospheric take on the genre. A lot of people prefer the Swedish version, Let the Right One In, so consider that if you feel like taking on another foreign vampire movie, but I prefer the American version, myself.
I also highly recommend The Green Room. It features Patrick Stewart as the sinister villain, and that alone makes it worth watching in my book. It's probably more of a thriller than a straight horror movie, but it still has its disturbing moments, and it is incredibly tense.
The Shallows is another one you might consider. I feel like it's gotten mixed reviews, so take this with a few grains of salt, but I personally loved it.
Lastly, I want to mention Lights Out. Put this in the category of Insidious and Sinister. This one genuinely creeped me out to the point where I had to turn some lights on in my house after I finished watching it. There's nothing really strikingly original about it, but it plays with fear of the dark in some very effective ways.