A Short History of Nearly Everything, Bill Bryson
Very easy to read, very rewarding, very enlightening.
I really can't fit Bryson's argument into any popular topics that abound today. He seems to go beyond many of them, though never arrogantly; just out of pure curiosity. And because of this curiosity, he manages to ask a much more pertinent question of humanity than any media, government or international organisation is currently screaming about.
I'm also impressed at the amount of work Bryson did to write this, all the more impressive in that he doesn't come across as hard-working.