This is a reading challenge including all the books recommended by Slowly Red's Grimdark Reader's Guide video on his YouTube channel.
I highly recommend his video and his channel as a whole for plenty more book reviews, Grimdark in particular.
https://www.youtube.com/watch?v=Ltd1l7UM1j0
The categories are also his.

Some get pretty dark and extreme so give the list a full read through first and make sure you're up to it 😈