Wow, thank you all so much for the recommendations!
I ADORE Joe Hill. NOS4A2 remains one of the books I've most enjoyed, ever! Also recently listened to the Audible production of Locke and Key, which was amazing! Admittedly, I was a little reluctant to read HSB as I didn't think his earlier work could be anywhere near as good, but read it over the past couple of days following the recommendations on here. It was genuinely scary, much better than anticipated. Not sure if I'll read The Fireman though (is it more sci-fi than supernatural? I'm beginning to realise that is the side of horror I prefer the most.
Fellside was great too, thank you to those who suggested it 
I read Dark Matter some time ago, and was offered Thin Air to review, but DNF as it seemed too similar to her earlier title. I may revisit though as more time has passed and my memory of DM may have faded more by now.
I've been putting off The Woman in Black and Let the Right One in as I've already seem the films (both the original, many times, and the disappointing US remake of LTROI). Should I read them anyway?
TheSecond I found Bird Box unputdownable!
I've just downloaded The Little Stranger, but have the feeling I may have read it before... Even if so, it would be a long time ago so will read on anyway 