How We Decide by Jonah Lehrer http://www.amazon.com/How-We-Dec... A fantastic and highly readable explanation of the balance between rational and emotional decision making.
Predictably Irrational by Dan Ariely http://www.amazon.com/Predictabl... Mentioned by many others. Outstanding experimentally-driven analysis of human irrationality.
Stumbling on Happiness by Dan Gilbert http://www.amazon.com/Stumbling-... Very engaging book, focusing mostly on how we go awry when we try to make decisions based upon our recollection of past events or beliefs about how we will feel in the future. (I also really enjoyed Haidt's Happiness Hypothesis, though it's less focused on decision making than this book is.)
On Being Certain by Robert Burton http://www.amazon.com/Being-Cert... A fascinating account of the neuroscience behind the feeling of "rightness" we get when we make decisions.
Nudge by Richard Thaler and Cass Sunstein http://www.amazon.com/Nudge-Impr... Great book that explains the disproportionate impact that initial conditions (priming, anchoring, etc.) have on our decision making.
Sway: The Irresistable Pull of Irrational Behavior by Ori and Rom Brafman http://www.amazon.com/Sway-Irres... Essentially, a quicker and more anecdotal version of Predictably Irrational.
The newest wave of decision making books are almost all focused on the irrationality aspect of human decisions, that do not seem to agree with economic models of decision making.
The "misbehaving" in the title refers to how empirical evidence shows human beings do not behave in line with economic theory predictions/ assumptions. Thaler has a talent for hilarity, sometimes unintended but I doubt it. The book is an easy read even though it repeats many things Kahneman's and Ariely's books have already dealt with. It is also a part-memoir of his journey as an academic/ researcher in this space.
Some great books by the previous answers. A recent book by the Nobel Prize winning psychologist, Daniel Kahneman is Thinking Fast and Slow which addresses many key concepts from the field of behavioral economics. A classic book from the past is Robert Cialdini, Influence: The Psychology of Persuasion
A pretty good and recent book is Split Second Pesuasion by Kevin Dutton which addresses key elements of persuasion represented by the acronym SPICE: Simplicity; Perceived self interest; Confidence; and empathy
The Teaching Company offers a great course, The Art of Strategic Decision Making. It has a great set of notes and looks at decision making from 3 perspectives: individual level; Group level; and Organizational level. On many occasions you can get the course on discount.
Lastly, an interesting book in the area of game theory but applicable to cooperative behavior and persuasion is Robert Axelrod's, The Evolution of Cooperation
Blackwell's Handbook of Judgment and Decision Making Edited by Koehler and Harvey ( Nathaniel Decker )
Kahneman and Tversky ( Stefano Bussolon ) the former is a Nobel Prize winner
Also, I got Thinking, Fast and Slow for Christmas and while I think its a little inaccessible--it is interesting. To be fair, I liked Nudge better which is about communication architecture in processes (I think this is golden for service designers as well as policy makers). My guess is the Blackwell Handbook is even better, because it contains multiple perspectives in this field.
The following book recocommendations sum up most of the contributions on this thread to date:
How We Decide by Jonah Lehrer
On Being Certain by Robert Burton
Predictably Irrational by Dan Ariely
Nudge by Richard Thaler and Cass Sunstein
Stumbling Toward Happiness, by Dan Gilbert
Sway: The Irresistable Pull of Irrational Behavior by Ori and Rom Brafman
Robert Axelrod's, The Evolution of Cooperation (game theory & cooperative behavior)
Buyology by Martin Lindstrom
Black Swan by Taleb
Fooled by Randomness by Taleb
Paradox of Choice by Barry Schwartz
The Psychology of Human Misjudgment by Charlie Munger
The Psychology of Judgment and Decision Making by Scott Plous
Checklist Manifesto by Atul Gawande
Seeking Wisdom by Peter Bevelin
Turning Numbers into Knowledge: Mastering the Art of Problem Solving
How to Measure Anything: Finding the Value of "Intangibles" in Business
A Whole New Mind by Dan Pink
Influence: The Psychology of Persuasion, by Robert Cialdini