Black Mirror is a dystopian sci-fi psychological horror TV show which is now a Netflix Exclusive. It's very good, and considered a spiritual successor to 'The Twilight Zone'.
So I really loved Black Mirror Seasons 1 and 2. I think White Christmas is just about the greatest TV episode in history. Just layers upon layers that come together in the most horrifying conclusion I've ever seen.
Season 3 is out on Netflix now. It's gonna be 12 episodes. I just got done with the second episode and I feel really destroyed. It was an incredible work of horror incorporating both terror and jump-scares with subtle mental horror. Definitely the 'scariest' episode.
If anyone wants a movie that is very similar in tone, I heartily recommend 'Ex Machina' which I thought was fantastic.