Certainly the best history of science I've read. The Making of the Atomic Bomb weaves the warp of modern physics with the woof of industrial warfare. Rhodes describes the principles of the bomb itself in terms accessible to a non-physicist; with equal care he lays out the cultural eddies and political evils which produced it.

I think the section on Oppenheimer is a much better introduction to the man than American Prometheus. The chapters on chemical warfare are also excellent introductions to that topic.

This is one of those books that makes you a better citizen.