I just finished reading Bastiat's
The Law - really interesting, and a quick read. I actually read most of it while traveling back and forth in WoW.
It's primarily an in-depth explanation of a fairly simple idea - that individuality, liberty and property are fundamental to human existence, that laws are a way to collectively protect those things against people who would try to harm them, and that therefore, laws which harm any of those things are unjust - justice being the protection of those inherent rights.
I definitely recommend this to anyone interested in politics. Be warned, though, it was a little slow through the middle - he spends a lot of time quoting opponents of his ideas and tearing down their arguments, which can get tedious.
Part of why politics and economics have been fascinating me so deeply the last few months is their enduring nature - this book was written over 100 years ago, and it's still extremely relevant.