Here are some favorites, organized by era, perhaps to be summarized at some point:
“Caesar” – Adrian Goldsworthy
“Charlemagne” – Alessandro Barbero
“A Distant Mirror” – Barbara Tuchman
“Elizabeth” – Alison Weir
“Frederick the Great” – Andrew Roberts
“Napolean” – Tim Blanning
“Bismarck” – Jonathan Steinberg
“The Rise and Fall of the British Empire” – Lawrence James
“Montcalm and Wolfe” – Frances Parkman
“His Excellency, George Washington” – Joseph Ellis
“John Adams” – David McCullough
“1776” – David McCullough
“Battle Cry of Freedom” – James McPherson
“Lincoln” – Gore Vidal
“A Stillness at Appomattox” – Bruce Catton
“Storm Over the Land” – Carl Sandburg
“Unto This Hour” – Tom Wicker
“Campaigning With Grant” – Horace Porter
“Theodore Rex” – Edmund Morris
“Dreadnought” – Robert Massie
“Wilson” – Scott Berg
“The First World War” – John Keegan
“Yanks” – John Eisenhower
“The Guns of August” – Barbara Tuchman
“All Quiet On The Western Front” – Erich Maria Remarque
“The Lost Battalion” – Thomas Johnson
“Paris 1919” – Margaret MacMillan
“Ataturk” – Andrew Mango
“FDR” – Ted Morgan
“No Ordinary Time” – Doris Kearns Goodwin
“Roosevelt” – Frank Freidel
“Truman” – David McCullough
“Eisenhower” – Stephen Ambrose
“Memoirs of the Second World War” – Winston Churchill
“Rise And Fall of the Third Reich” – William Shirer
“The Last Lion – Visions of Glory – 1874-1932” – William Manchester
“The Last Lion – Alone – 1932-1940” – William Manchester
“The Last Lion – Defender of the Realm – 1940-1965” – William Manchester
“The Red Horse” – Eugenio Corti
“In The Garden of Beasts” – Erik Larson
“An Army at Dawn” – Rick Atkinson
“The Day Of Battle” – Rick Atkinson
“Guns At Last Light” – Rick Atkinson
“The Wild Blue” – Steven Ambrose
“Enola Gay” – Paul Tibbets
“D-Day” – Stephen Ambrose
“Is Paris Burning” – Larry Collins
“Goodbye Darkness” – William Manchster
“Monte Cassino” – Matthew Parker
“Flags Of Our Fathers” – James Bradley
“The Forgotten Soldier” – Guy Sajer
“Indianapolis” – Lynn Vincent
“With The Old Breed” – E.B. Sledge
“Helmet For My Pillow” – Robert Leckie
“Before Their Time” – Robert Kotlowitz
“Foot Soldier” – Roscoe Blunt
“General of the Army George C. Marshall” – Ed Cray
“Joseph Stillwell and the American Experience in China” – Barbara Tuchman
“Dulles – Biography of Eleanor, Allen and John Foster Dulles” – Leonard Mosley
“Memoirs” – George Kennan
“Thunder Out Of China” – Theodore White
“Acheson” – James Chace
“Once An Eagle” – Anton Myrer
“Lyndon Johnson – Means of Ascent” – Robert Caro
“The Best and The Brightest” – David Halberstam
“Kennedy” – Ted Sorenson
“The Death Of A President” – William Manchester
“Robert Kennedy and His Times” – Arthur Schlesinger
“Lyndon Johnson And The American Dream” – Doris Kearns Goodwin
“Vietnam” – Stanley Karnow
“In Retrospect” – Robert McNamara
“The Price of Power” – Seymour Hersh
“Matterhorn” – Karl Marlantes
“A Bright Shing Lie” – Neil Sheehan
“Long Gray Line” – Rick Atkinson
“When I Was A Young Man” – Bob Kerry
“Fortunate Son” – Lewis Puller Jr.
“My American Dream” – Colin Powell
“Grand Inquests” – William Rehnquist
“The Power Broker” – Robert Caro
“Cities And The Wealth of Nations” – Jane Jacobs
KULTURONOMY 