Gritty realistic, adult, dark, black and gray morality.
1. First Law by Joe Abercrombie - Its not as much fantasy as those two. It has magic, but most of the times its more about swords, axes, hammers, bows, spears, etc. I.e realistic action. Most badass book I've read. Characters vary from bad to worse. Ironic tone makes it one of the funniest books I've read even though its totally serious at the same time.
2. Broken Empire by Mark Lawrence - It has first person pov. Worst main character ever. He rapes two girls and kills one of his mates without any remorse in first few pages. Totally worth reading. Its fresh, entertaining, interesting...
These have dark/gritty/adult stuff too but mainly go with more fantasy part and more Epic Fantasy type stories and less black and gray morality.
3. Demon Cycle by Peter V. Brett - Badassery + Epicness really well done. One of my most favorite books. Awesome story, characters, setting...
4. Night Angel by Brent Weeks - Same as third.
5. Malazan book of the Fallen by Steven Erikson - First Law with lots of magic and more mystery.
Now these have adult stuff and grittiness but less darkness and more epicness.
6. Mistborn, Elantris, Warbreaker, Way of Kings by Brandon Sanderson - Epicness over 9k. Especially in Way of Kings and Mistborn. Most original and well developed magic-systems and worldbuildings. All these books are connected and imo create greatest fantasy universe ever written. These books are epic fantasy at its highest. Warbreaker's pdf is available on author's site. Its really good but Mistborn and Way of Kings are best.
7. Kingkiller Chronicle by Patrick Rothfuss - Most well written fantasy imo. Mystery. Awesome story. Original magic-systems and worldbuilding. It has first person point of view. My personal number one.