The Civil War by Shelby Foote
Best Civil War book every! Read it about ten years ago. Represents almost a year out of my life, but inspired me to take a week's vacation in Virginia just to visit Civil War battleground sites in Pennsylvania and Virginia.
I was saddened when Shelby Foote passed away in 2005 (at the age of 88), but what a tremendous legacy he left with his trilogy. While a Southerner through and through, Foote's historic account of the Civil War is probably the most fair and balanced.