Thinking, Fast and Slow by Daniel Kahneman. Wonderfully accessible and engaging look at the two 'systems' of thought; active, conscious thinking (eg when you're facing a maths problem) and unconscious 'invisible' thinking (eg looking at a maths problem and deciding that you need to think about it). Full of examples and studies - sometimes he'll describe the way we react to something on a page and you can actually feel yourself doing it. I've never read a psychology book in my life but I'm really enjoying it and it's changing the way I think already. Highly recommended!
I also bought Lullaby by Chuck Palahniuk and Hopes & Prospects by Chomsky yesterday, looking forward to getting into them.