China Mieville's Perdido Street Station is a seriously weird book. Mieville apparently regards it as fantasy, and in some ways it reads as fantasy, but it could also be considered science fiction. Enough stuffing the story into a pigeonhole, though. The story could be considered a quest, but there's a lot more going on than that. Anime fans will recognize a lot of familiar tropes: the corrupt, vicious and yet bumbling government, the blending of science and magic together so you can't really tell where one picks up and the other leaves off, to name the major ones that jump right out at you. I was also reminded of M. John Harrison's The Centauri Device, which likewise depicts a group of antiheroes engaged in apocalyptic struggle in a seedy, grimy, nasty universe the likes of which are seldom seen in American SF. That having been said, the story is gripping and horrific, with desperate measures and super-science being employed on a scale that would have had Doc Savage and Blackie DuQuesne alike nodding in approval.
I'm going to have to keep an eye out for Mieville's other stuff. New Crobuzon is an ugly, ugly city, but there's some awesome stories going on there.