Mankiw on non-textbooks

On his blog Greg Mankiw reports on a conversation he had recently with a student:

Student: Professor Mankiw, if you could recommend just one book, what book would it be?

Me: Am I allowed to recommend my favorite textbook?

Student: No. Textbooks are disallowed.

Me: In that case, I'll suggest Milton Friedman's Capitalism and Freedom.

Student: That's funny. That's the same answer I got when I asked this question of Professor Summers.

One wonders how often he would get that answer if he increased his sample size above two. Friedman was one of the great economists of all time and his book is an excellent read for economists and non-economists alike. More students need to read it.

But what other answers to the question could he get? What other readable, but serious, books could be recommended? The Road to Serfdom? Economic Sophisms? An Inquiry into the Nature and Causes of the Wealth of Nations? The Theory of Moral Sentiments? On Liberty?