For the outset of WWI Barbara Tuchman's 'The Proud Tower' is a great of European society during la belle epoque and the onset of the war. Her other volume, 'The Guns of August', is a wonderfully written view of the turmoil in Europe during the first month of the war as things started to heat up.
Agreed, I love those books.
Start with the Rick Atkinson Liberation Trilogy book one An Army at Dawn. Easy to read perspective on the North African Campaign which starts the U.S. involvement with the war.
Good book, but "starts"? Pearl Harbor, the Philippines, Coral Sea, Midway, Guadalcanal, Battle of the Atlantic, VIII Bomber Command?
Anyway, some personal favorites...
WW1:
Dreadnought by Robert Massie is a very readable account of the Britain vs Germany naval arms race and international rivalry leading up to the war. It has some technical shortcomings, but is more than adequate for most readers.
Somme Success, Bloody April and
Aces Falling by Peter Hart. Great accounts of the ebb and flow of the first air war, with equally illuminating focus on the equipment, tactics and people.
The Rules of the Game by Andrew Gordon. A very in-depth and technical but at the same time readable and riveting story of the culture and leadership of the British Royal Navy, in an attempt to answer the question of why they were unable to "close the deal" on the German fleet in 1916.
WW2:
Six Armies in Normandy by John Keegan. A good account of Overlord and an excellent analysis of the strategic background.
Silent Victory by Clay Blair Jr. Long and rightfully so, this is the definitive account of the submarine war against Japan, from the history of the US sub service to the strategic picture to the action on individual boats. His
Hitler's U-Boat War is also excellent.
Stalingrad: The Fateful Siege by Anthony Beevor. An outstanding account of the long pivotal battle, but also gives a good background on the Eastern Front from Barbarossa on.
Shattered Sword: The Untold Story of the Battle of Midway by J. Parshall and A. Tully. As good an account as has emerged of what may be the most important US battle of the war. It draws from much broader Japanese sources than previous works.