No, not Milton Friedman. Murray Rothbard! There is an anti-Rothbard cult which I simply don't understand. There's also, of course, a pro-Rothbard cult. Both are wrong, although the pro-Rothbard cult is much less wrong than the anti-Rothbard cult. I just think there is danger is 'cults of personality.' I never met Murray Rothbard. Would that I had! But he died in my freshman year of university, and I'm Canadian where the spirit of liberty is much less developed. So I didn't even hear of Rothbard until 2005/2006 when I heard Peter Schiff talking about real estate bubbles and I started digging into Austrian economics thereafter.
I read Man, Economy and State and found it to be a very good economics textbook. It is Austrian because of the methods employed (verbal logical as opposed to symbolic) but not because of the conclusions. Most conclusions are not that different from neoclassical economics. What is different is the deep attention paid to production. No school outside of the Austrian school takes the structure of production & capital as seriously. It's an important defining characteristic.
Moving on, I've read a few other books by Rothbard. The man is a virtuoso of the English language, which makes his incredible volume of writing all the more impressive. Plus - typewriter! No word processors in the '60s. It will take me longer to read his contributions than it took him to write them.
His "For a New Liberty" is an excellent vision of what a libertarian society would look like and how it would operate. He tackles all the hardest issues, like private policing and courts. You can argue with the points he makes, but he has some very good arguments.
"History of Money and Banking in the United States: The Colonial Era to World War II" is an excellent history book. Not filled with simplistic aggregates of money and so forth, this is a nitty-gritty tale of the people and events involved in shaping the current monstrosity that is the U.S. bank system. You could make a mini-series out of this book. Ever wonder why the Wall Street guys love the Fed? This book contains the answer.
Currently, I'm reading "Classical Economics: An Austrian Perspective on the History of Economic Thought" which is post-Adam Smith to early 20th century. Some excellent work here too, as Rothbard gets deeply into the economic controversies that motivated all the writers he reviews. This helps the reader understand the contributions of each economist and how they advanced the science. Reading this type of book also shows how many old arguments keep coming up. I think all students of economics (formal and informal) should know their history, and this book and its predecessor "Economic Thought Before Adam Smith" are excellent places to start. And stop if you haven't much time.
Finally, I was motivated to write this post by the excellent Tom Woods, who illustrates Murray Rothbard's character and contributions in this moving presentation: http://www.lewrockwell.com/lewrockwell-show/2012/07/31/297-the-anti-rothbard-cult/