I love Mercedes Lackey's 500 Kingdoms series. I love the way she works in any number of fairy tales into a cohesive single story. The Fairy Godmother is still my favorites, but Fortune's Fool is definitely the second on the list.
This book is set in the world of Russian fairy tales, and works in the sea kingdoms as well. It's a great play on the idea of the wise fool of fairy tales, and is just an enjoyable story. I read it in two evenings, and only took that long because I was interrupted last night.
Love these books. Complete guilty pleasure. Enough said.