What is your favorite grimdark work outside of the Warhammer universe?

I'm not super familiar with grimdark Sci Fi outside of Warhammer. But I'm pretty familiar with Warhammer, and I'm reading First Law in the fantasy context and love both. I'd like to see if there is something else out there in terms of Sci Fi. I'm not picky on medium (books, shows, movies, whatever), and I don't care too much if something is borderline grimdark or fully in the genre a la Warhammer. I recognize the term isn't defined well, and people could endlessly debate if something is grimdark or not. I'm just interested in that general sphere of work.