It might change you too, if you pick it up and read it with an open mind.
The thesis of this book can be summed up as "libertarianism is a justified social philosophy and only it is capable of resolving our social problems in an economic and moral way." Other reviews can provide more detail, in fact you can read the whole book online for free if you know where to look and check it out yourself, or use the "look inside" feature.
Establishing that private property rights are ultimately justified, Rothbard tackles all the big issues of his day and our own -- war, the business cycle, environmental conservation, the public sector, welfare, education, personal liberty, etc. When he analyzes a problem and offers a libertarian solution, prepare to be have all your assumptions about the world challenged like you never thought possible, even if you are naturally sympathetic to the "lite" libertarian position of limited government. Rothbard does not pull punches -- only private property rights are justified, and therefore the government, which is intrinsically and institution that violates private property rights, is evil by nature and should not exist. The fact that libertarianism would be economically better is secondary to the moral issue. That is why this book is "hard"-core libertarianism and it is so valuable. (Most libertarian literature is grounded in economic arguments.)
That's the core of the book, essentially. For the remainder of this review I ask you indulge my personal story as to what this book meant to me when I read it -- perhaps that will produce a more compelling a reason to read it for some people.
This is the book that converted me to libertarian anarchism about 10 years ago, Before that, I was your typical minimal government "classical liberal" sort of guy. But in chapter 2, "Property and Exchange", I came across the argument that shattered my simplistic conception of the world and made me realize that no alternative to libertarianism is morally acceptable.
It wasn't that easy, of course. I grappled with Rothbard's arguments in my mind for a long, long time. I was figuring they were so radical they MUST be wrong, although the arguments were so clear and decisive it seemed oppressively difficult to say _why_ he was wrong. Eventually, I had to concede that Rothbard is, quite simply, correct on the issue of justice, and there is no honest way around it.
And this isn't even the hardest part! When it came time to face Rothbard's arguments on the superiority of PRIVATE COURTS and PRIVATE POLICE, I rather dogmatically assumed he had to be wrong. I could accept libertarian solutions to almost everything, being a classical liberal n' all that, but private courts? Private police?!? Come on... but even here, Rothbard is consistent where the classical liberal is not, and most importantly I found his arguments to be unassailable after long, careful, agonizing consideration. It is easy enough to agree that taxation is robbery, yet think taxing people to pay for socialized police services is legitimate just because "it has to be that way." But Rothbard attacks this inconsistency and demonstrates that socialized courts and police DON'T WORK, anymore than the post office, the Department of Education, or whatever, and government services are immoral anyway.
Needless to say, I am a Rothbardian now. People will say "Rothbard's solutions are impractical", which is simply false. What is impractical is the government, and liberty is the most practical solution of all. Not only that, but more important liberty is JUST. Let this book show you why -- it is the best introduction to libertarian-anarchism, along with another charming book by Dr. Mary J Ruwart called _Healing Our World_.