Ain't Nobody's Business If You Do : The Absurdity of Consensual Crimes in Our Free Country is the best book I've ever read.
I stumbled across it while doing a research paper on the benefits of legalized prostitution in college. And my brother ran into it too. We were surprised to find that we both had it and loved it. I barely missed the opportunity to meet Peter and it was his death that got me to stop just voting for Libertarians and to start being an activist. I have sworn to his mother than I will work until my dying breath to end the drug war and make all drugs 100% legal so more people aren't murdered by our government like he was. I won't stop there though. I won't stop until we've got a Libertarian president, Libertarian controlled congress, and a mostly Libertarian USSC. I might die first, but I'll pass the torch to my kids.
If you want to read the book before you decide to pay for it or not Peter McWilliams made it (and his other books) available online for free. Just use the link I made above and you can read it online.