I am a total mood reader. I pick what book I'm reading based on what I am in the mood for at that very moment. When I have no specific genre craving, it makes it hard to get in to a book. That's why I love it when a mood suddenly strikes.
These events send me bolting to my bookcase, bookstore, or a library to grab a book that fulfills my sudden craving. It makes me happy and gives me a ton of reading energy. When I find that perfect book for my sudden reading mood, I've been known to plow through it in record time... usually because I neglect sleep.