First, I saw your scariest movies post, and there was a section of movies you listed that you haven't seen yet. From that list, I'd recommend the REC movies. Granted, I haven't seen the others you listed there either, so this is not to say anything about the others on the list. But yeah, I'd definitely recommend the REC movies.
Second, as for additional recommendations that I didn't see on any of your lists:
Orphan
Sinister 2 (this is assuming you haven't seen it. I saw that you've seen the first one)
The Babysitter and The Babysitter: Killer Queen (these were some fun movies found on Netflix)
Emelie (another babysitter themed movie, although a bit more serious than "The Babysitter" movies)
The Fear Street movies (part 1, 2, and 3) on Netflix were OK. I'd say at least worth maybe giving a shot sometime.
The House of the Devil