Yes yes, horror is usually garbage, but I like reading it.
Can you recommend some good horror books? Preferably not something that is under "must read" or classics or really well known. Some things you picked up and found great. I also prefer horror short stories since they're without fillers, usually.
Again, I did read stuff from Clive Barker, Thomas Ligotti, House of Leaves, Lovecraft, Poe, etc., even Stephen King short stories collection. But I'm looking for something better, maybe even actually scary.
>horror is usually garbage
I've yet to find anyone who scares me more than Ligotti, really. Not only that, but who writes better. I love that his stories read like fragments of someone's nightmares, and that he is very little concerned with plot or character development. To him plot and characters are just an excuse to write about, and I quote him here, the universe as some sort of enchanting nightmare.
I've read a lot of modern weird fiction, from the commercial types of Laird Barron to the more cerebral types like Michael Cisco, and some of it is fantastic and I love it. But it doesn't top Ligotti as far as writing a pure expression of terror goes.
Off the top of my head I can recommend Hell House by Richard Matheson and Ghost Story by Peter Straub. I guess you read the Books of Blood by Clive Barker already, if not do it.
Also pic related.
What Ligotti do I read?
Pic related is amazing, >1000 pages of great "weird" novellas and short stories
Plowed through it in a week, lots of starting points, like Ben Okri, Fritz Leiber, Jean Ray, Clark Ashton Smith, Saki
The one in OP is very Lovecraftian and I found it a bit tedious towards the end, it was too descriptively and thematically repetitive. I'd recommend Teatro and My Work Is Not Yet Done over the collection, he really gets into his own stride with it.
I honestly believe The Nine Billion Names of God (Arthur C. Clarke) is the best horror story ever written. I have a rather loose definition of horror, but damn if I don't get goosebumps every time I read that story.
Teatro Grottesco is not one of his better collections IMO; it's fairly uneven and repetitive. Yes, almost all of his stories are centered around existential horror, and tedium is definitely one of his favorite subjects. If you didn't like every story in Teatro but found some of the images and ideas interesting, check out Songs of a Dead Dreamer, which is much easier to find nowadays thanks to the Penguin publication, or The Conspiracy against the Human Race, which is a nonfiction work that elucidates his thematic purposes as writer very clearly.