Consciousness: Confessions of a Romantic Reductionist, by Christof Koch, is a very thought-provoking book. I majored in and did graduate study in philosophy (and minored in and took graduate courses in psychology), so this just-published book is what I consider to be an easy read.
I find Koch's thesis, that consciousness is simply a property of a sufficiently complex system, quite reasonable. I believe his point is that what we call consciousness is in fact nothing but self-awareness of a complex system in operation. It is not, "I think, therefore I am," but rather, "I am, therefore I think." And that's all there is to it.