Not necesarily grimdark or dark fantasy (some might be epic fantasy or military fantasy and so on), but with darker undertones, grey characters and serious, mature writing and story. No YA here, full adults readers only!
#1 of 7 in A Song of Ice and Fire
1996 • 3,287 Readers • 819 pages • 4.4
#1 of 3 in Manifest Delusions
2015 • 117 Readers • 495 pages • 3.8
2021 • 25 Readers • 512 pages • 4
2018 • 2,802 Readers • 409 pages • 4.2
2018 • 3 Readers • 429 pages • 3
2009 • 8 Readers • 406 pages • 3.8
#2 of 12 in The Elric Saga
1976 • 73 Readers • 352 pages • 3.6
#1 of 1 in Strange & Norrell
2004 • 1,245 Readers • 865 pages • 4
#1 of 3 in The Chronicles of Thomas Covenant the Unbeliever
1977 • 254 Readers • 369 pages • 3.2
2021 • 16 Readers • 394 pages • 4
#1 of 3 in Bloodsounder's Arc
2012 • 43 Readers • 269 pages • 3.7
#1 of 10 in The Chronicles of the Black Company
1984 • 277 Readers • 320 pages • 3.6
2013 • 19 Readers • 3.6
#1 of 3 in The Prince of Nothing
2003 • 294 Readers • 657 pages • 3.8
#1 of 5 in Chronicle of the Unhewn Throne
2014 • 346 Readers • 493 pages • 3.9
#1 of 3 in The Five Warrior Angels
2016 • 195 Readers • 800 pages • 4
#1 of 3 in The Riyria Revelations (Omnibus)
2008 • 569 Readers • 704 pages • 4.1
2019 • 53 Readers • 432 pages • 3.5
#1 of 3 in The Black Iron Legacy
2019 • 158 Readers • 544 pages • 3.8
2015 • 716 Readers • 390 pages • 4
#1 of 7 in Gentleman Bastard
2006 • 1,885 Readers • 745 pages • 4.3
2 Readers • 5
#1 of 3 in The Kingkiller Chronicle
1 • 2,701 Readers • 669 pages • 4.4
#1 of 5 in The Book of the New Sun
1980 • 511 Readers • 276 pages • 3.7
#1 of 3 in A Land Fit for Heroes
2008 • 159 Readers • 450 pages • 3.8
#1 of 4 in The Masquerade
2015 • 495 Readers • 400 pages • 3.9
2018 • 22 Readers • 480 pages • 4.3
6 Readers • 5
#1 of 2 in The Vanguard Chronicles
2020 • 17 Readers • 356 pages • 4
8 Readers • 4.3