I love this contest, I wish I could post multiple entries because it's so hard to choose just one! :)
But for me, my favorite book is Haruki Murakami's 1Q84. It's about Aomame who got trapped in a parallel universe with 2 moons, and also about the ghost writer Tengo who got involved with the writer he's writing for. This became a favorite because I love how the author had separate yet intertwined stories. The narrative is superb as well, very Japanese style. Subtle yet chilling. It's really amazing! 