Steve Landsburg is putting out a revised edition of his classic, The Armchair Economist. Full details here.
Although Murray Rothbard is the economist who most influenced me, Landsburg’s book might be the single most influential volume in terms of how I try to relay economics to the layperson.
What may interest you is that I actually disagree with a lot of the things Steve says in the book, but he says them so clearly that I think we are all wiser after I blow him up…. For example, see this.
I mentioned to Steve in the comments at his blog that I had actually written him a critique back when I was about to start grad school. I’ll see if I can dig that up.