American Property: A History of How, Why, and What We Own (Harvard 2011) is one of his best (though I seem to say that about every one of his books). This book may become a centerpiece of my Property Theory Seminar in the Spring.
The Case for a Carbon Tax: Getting Past Our Hang-ups to Effective Climate Policy (Island Press 2011). In it, he argues for a carbon tax as preferable to cap-and-trade, traditional regulation, or alternative energy subsidies for curbing greenhouse gas emissions because it is simpler to design, implement, and administer. His arguments are entirely persuasive. Although, I'm not sure it makes a carbon tax any easier to actually enact as a political matter. In fact, I'm not sure that policy makers (aside from the bureaucrats of the European Commission and, perhaps, the State of California) are ready to institute an effective climate policy of any kind.