Michael Chabon - 'The Yiddish Policemen's Union', and also 'The Final Solution'.
Michael Chabon is the absolute best modern writer I've come across.
Clive Barker - Abarat: Days of Magic, Nights of War
As mentioned above by aliengirl, Gaiman is great!
I hadn't read fantasy in years until I decided to pick up Neverwhere. It got me hooked on Urban Fantasy. However, I was not nearly so keen on The Ocean at the End of the Lane, which was too whimsical for my taste. Neil wrote a short story some years back called 'The Problem of Susan' which took a serious stab at what CS Lewis did to the poor girl in his Chronicles of Narnia. Best short story I've ever read.