Michael Swanwick's The Iron Dragon's Daughter. This is fantasy for adults: complex flawed characters, a world rich in detail, multitude of characters who live and do things for their own sake rather than to advance a plot point or help the hero. Utter disregard for conventions and cliches of the genre. A hero who is an anti-Mary Sue. Endless inventiveness of the author.

To my taste, this novel is what books like The Kingkiller Chronicles promise, but then utterly fail to deliver. But if you're a fan of Rothfuss, try Swanwick anyway, and you might get a fuller and richer taste of what you like.

I've also read a science fiction novel by the same author, Stations of the Tide, which won a Nebula in 1991. It's also very good. In it, a nameless bureaucrat of the interplanetary government is pursuing a self-declared magician (who's suspected of smuggling restricted technology) across the surface of a planet where half the surface is about to get flooded for many years, and a great migration of the populace is imminent. One of the themes is unfriendly AI - the Earth with its entire population had suffered a horrible fate in the world of this novel, which is discussed and explored in one of the episodes, although it's not a major plot device.