Sinister: For some reason, this is the most utterly horrifying movie I have ever seen, and I've got quite the catalog I should like to think. From start to finish this movie truly masters the art of creating an unsettling atmosphere, and by absolutely astonishing audio it keep you on your toes all the way through. It seems to love luring you into these situations where you expect some big, scary monster to pop up on your screen - And your heart races long after you realize that it's just not going to happen!
A must see for anyone who wants something other than just a bundle of cheap jumpscares and cliche monsters and murderers.
Hellraiser 1-3: Absolutely amazing series. Even thought that their old, they have aged far better than most horror films of the same era. Yet when compared to ol' Myers or Jason, Pinhead is quite the hidden gem - The guy unfortunately shoved to the back of the line when it came to getting attention. The movies, especially the first two, are generally based around extremely dark eroticism, with demons who seek to inflict so much pain and pleasure on their victims that they won't be able to tell them apart anymore.
Hellraiser - Bloodlines: If you're feeling adventurous - I actually like this one, but it's very much a hit'n'miss story.
Hellraiser - Deader: If the weird sci-fi themes of Bloodlines isn't your thing, Deader is honestly the only addition to the franchise that feels like it belongs. This is mostly because that most of the later parts of the franchise weren't actually Hellraiser-scripts to begin with, but started out as completely different IP's, which then got Pinhead slapped on the box to sell some extra copies. Hellworld, Revelations, Hellseeker - I wouldn't recommend bothering with them, but if you get really into the series, you might want to. (But.. Yeah, you'd probably be disappointed.)
Insidious: Amazing horror film, with a very interesting and unique twist on a classic ghost story. A series of great twists and turns lead to one of the best cliffhangers I've ever clung to!
Insidious 2: Luckily, unlike me, you won't actually have to wait to have your curiosity satisfied - This film is far more horrifying than the first, but just as great a watch! It'll definitely leave you feeling quite uneasy throughout.