Even though I don't write fantasy (instead I write historical novels like Sinful Folk), I absolutely love the intricately plotted, surreal, supernaturally-infused work of Tim Powers.
In fact, I've tried to buy everything he's ever written. So yes, I'm a bit of a Tim Powers completist.... and here's the proof.
I highly recommend Declare, if you want to learn how to write a well-plotted spy thriller, Last Call for an amazing Poker + Tarot story or Stress of Her Regard (for the best vampire novel ever written, yes, for real, that never mentions the word "vampire" -- oh, and it also features Lord Byron, the Shelleys, etc.)