Depending on what you like:
Just watched "Safe" on Netflix which is based on a Harlan Coban book, I watched it because I was 90% sure I'd read and enjoyed one of his books. Its about a father who's daughter has gone missing as has her boyfriend. It sounds simple and I thought I'd sussed it in the first scene but it's a whole lot more twisting than that and it wasn't until right when the "reveal" happened that I knew what happened. Also, aside from perhaps the police, the characters weren't stupid. Stupid characters making stupid decisions annoy me, these made intelligent insights.
Slasher- this is on Now TV and I *think* Netflix- there are apparently 3 series however I cant seem to find the 3rd and according to reviews it goes downhill a lot. Season 2 is the best. VERY gory but not in a silly way if that makes sense. I hate slow motion kills with the blood slowly spurting. Feel it removes any tension built up. Again you can't figure out the killer until right near the end. In the 2nd season especially, due to where the characters are (remote ski lodge) I actually felt the tension and isolation. If you've played Until Dawn on the ps4 it is similar.
Line of Duty.
Luther although I found the last 2 series were bordering on silly. They just discover a body but he is swanning off to faff around with another character. Also the focus on this other character removes some of the focus on the actual killers, I feel the killer could have really been developed as what they were doing was scary however its almost a background story. In the first couple of seasons it's more about the killer and him solving the case which is much better.
I was reading a review today about "Eerie" on Netflix has anyone tried it? Apparently it's freaking people out so much they cant sleep however apparently the House of Haunted Hill did that however I fell asleep during it so I'm sceptical