Dubious Quality

It's based on the Ken Burns documentary, and it's a genuinely brilliant book. I've read a fair amount about the Vietnam War in the past (particularly, the degree to which North Vietnamese intelligence agents penetrated the South to the highest levels of government), but there are so many additional details here, based on recently declassified information.

The degree of incompetence by which the war was administered (both by the South Vietnamese and the U.S.) was staggering, to a degree almost beyond comprehension. 

If you want to have a much better understanding of how U.S. politics and military policy work, this is a phenomenal read. And on a personal level, it's excellent at focusing on individuals and their own experience in war.