These are in no particular order. I'm always on the lookout for good military history reads, so please do share your own favorites.
JFC Fuller's 'Military History of the Western World' - This three book series is a history buff's dream. Not only does Fuller explain the significant battles and campaigns in great detail, but also speculates on why they were important. For example, he postulates how Clive's victories at Plassy and Pondichery enabled the Brits to use the wealth of India to fuel the industrial revolution. General Fuller was also very controversial at times. For instance, he seemed to have a near-hatred of the Protestant cause when discussing the Thirty Years War. Also, I'm sure it outraged many when he stated that not only was the Battle of Stalingrad a defeat for the Reich, but a defeat for the West as well. Still a fascinating read, no matter if you always agree with General Fuller or not.
David Chandler's 'The Campaigns of Napoleon' - I don't think I've ever read a history book that was such an exciting and a relatively easy read despite its great length. If you have only one book on Napoleon, this one is it.
Paul Carel's 'Hitler Moves East/Scorched Earth' - Carel does for the Eastern Front what Chander does for Napoleon. I think where Carel excels is in his ability to write equally well about the war from a high level, and then take the reader down into the trenches on the turn of a dime. There are so many great moments that it's hard to recount them all here: The Russian counterattack at Yelnya, the Kiev encirclement, the Moscow campaign, the long and bloody road to Stalingrad, Manstein's backhand blow, the apocalyptic Kursk battle, the attempted Korsun breakout. Although he tells the story mostly from the German perspective, I still consider these two books the definitive work on the Russo-German War, and possibly the best military history books ever written.
The Fall of Rome: The Military Explanation' by Arther Ferril - This one is a relatively short and sweet read, but still one of the better books I've read on the latter Empire. A couple of excerpts: "Emperor Julian's attempt to restore the old Roman gods and check the spread of Christianity where anachronistic and inconsequential. His loss of several provinces in the East (in the wake of his failed Persian campaign), however was another matter entirely." "In preparing for the Persian campaign, Julian's army had amassed an enormous mound of horse fodder. It was so big that when some soldiers attempted to remove some fodder from near the bottom, it collapsed and killed fifty men!" Such anecdotes speak volumes about the Roman supply issues.
Shelby Foote's 'Civil War Trilogy - The definitive work on the American Civil War. An easy read and a lot of great detail. Although Foote was more than a little sympathetic to the South, he managed to stay relatively unbiased, and did a great job breathing life in to all the prominent soldiers and politicians. Also, he eschewed political correctness in his praise of the military genius of Nathan Bedford Forrest.
Bernard Fall's 'Hell in a Very Small Place' - The definite work on the Siege of Dien Bien Phu. Like Carel mentioned above, Fall does a great job going back and forth between the high command and the men on the battlefield. The paradrops and action were described so vividly that I felt like I was witnessing them. Fall also writes about the many colorful personalities, including the 'Angel' of Dien Bien Phu, and the brothel that became nurses to the garrison. Also of note was his discussion of the controversial Operation Vulture (X-File ; which included the possibility of using Nukes against the Viet Minh to save the French garrison.
Barbara Tuchman's 'The Guns of August' - One of the most exciting history books I've ever read. Gripping, tense, and unforgettable. The only trouble is, she ends it right before the miracle of the Marne. Her description of the Battle of Tannenberg was fantastic.
Tolstoy's 'War and Peace' - Although an historical fiction, Tolstoy does a great job describing the 1805 and 1812 campaigns in much detail, and I still get shivers when I think of his narrative of Napoleon's retreat from Russia. Possibly the greatest historical novel ever written.
Herman Wouk's 'The Hope' and 'The Glory' - Covers the entire history of modern Israel from the '48 up to the invasion of Lebanon in the early 80's. Although these are of course works of historical fiction, Wouk's history is accurate and the books are a very entertaining read. Lots of memorable moments including the paradrop at Mitla Pass, the Battle of the Chinese Farm, and the Raid on Entebbe. Someone looking for a good overview of the Arab-Israeli Wars could do much worse than these two books.
Ladislas Farago's 'Patton: Ordeal and Triumph' - This was the book (along with Omar Bradley's autobiography) that Francis Ford Coppola used to write the screenplay for the film 'Patton'. 'nuff said.
Oh well, back to my 'Case Blue' drive on Stalingrad (John Tiller's WW2 Campaign series).