deLint writes Fantasy mostly, but he became famous for what they call "Urban Fantasy." The books I've read by him (which do not include Blue Girl or Widdershins, sorry. They're on my list, but it will be a while before I get to them) usualy depict a world, the modern world, where the land of Faerie is overlaid on top of it, invisible to mortals.
In Jack the Giant Killer, a young lady becomes the "Jack" (sort of an official magically-charged community trickster or Clever Hero) for the city of Ottowa after she saves a... well... a lawn gnome from the Wild Hunt of celtic lore)
In Greenmantle, a soldati (hit man) stumbles across a different version of the Wild Hunt pursuing a stag that's a personfication of Mystery itself. Pretty neat stuff.
deLint also wrote the book that, I think, inspired FASA games' Shadowrun,
Svaha, and about a million other things.
Here's a link:
http://www.librarything.com/author/lintcharlesde&all=books