My five favorites:
Robert Blake, Disraeli
Hugo Thomas, The Spanish Civil War
Arnold Ludwig, King of the Mountain
Nicholas Basbanes, A Gentle Madness
Miguel de Cervantes, Don Quixote
More:
The Rise of Theodore Roosevelt, Edmund Morris
Theodore Rex, Edmund Morris
Mussolini as Diplomat, Richard Lamb
The Great Terror, Robert Conquest
Catherine the Great, John T. Alexander
Hostage to the Devil, Malachi Martin
Freedom from Fear, 1929-1945, David M. Kennedy
Educating for Liberty, Lee Edwards
A Personal Odyssey, Thomas Sowell
Race and Culture: A World View, Thomas Sowell
The New History of the World, J.M. Roberts
Colossus, Niall Ferguson
State-Building, Francis ***uyama
Faith of the Early Fathers: Three-Volume Set, William A. Jurgens
Human Love in the Divine Plan, John Paul II
The Unmasking of Oscar Wilde, Joseph Pearce
Rapture Culture, Amy Johnson Frykholm
Fear and Trembling, Soren Kierkegaard
Russia in Search of Itself, James H. Billington
Blood, Class and Empire : The Enduring Anglo-American Relationship, Christopher Hitchens
Marathon, Jules Witcover
The Furrtails, Shandi Finnessey
The Betrayal of Dissent, Scott Lucas
The Jesuits, Malachi Martin
Lincoln, Richard J. Carwardine
Air Power, Stephen Budiansky
Death on a Friday Afternoon, Richard John Neuhaus
A Secret Life, Benjamin Weiser
Inside George Orwell : A Biography, Gordon Bowker
Mr. Blue, Myles Connolly
Bobby Fischer Goes to War, David Edmonds
America's Great Depression, Murray N. Rothbard
Recovery of Freedom, Paul Johnson
Affirmative Action Around the World, Thomas Sowell
Aristotle's Children, Richard E. Rubenstein
Shows About Nothing, Thomas S. Hibbs
The Seven Ages of Man, George William Rutler
Oriana Fallaci: The Woman and the Myth, Santo L. Arico
It's Getting Better All the Time, Stephen Moore
Khrushchev: The Man and His Era, William Taubman
John Stuart Mill: A Biography, Nicholas Capaldi
Republican Party Reptile: Essays and Outrages, P. J. O'Rourke
Peace Kills: America's Fun New Imperialism, P. J. O'Rourke
On Paradise Drive, David Brooks
The Real Jimmy Carter, Steven F. Hayward
The Last Pagan, Adrian Murdoch
The Rape of the Masters, Roger Kimball
Blood and Ivy, Andrew Hazlett
The Kennedys: An American Drama, Peter Collier
Who Killed Homer?, Victor Davis Hanson
Greek Ways, Bruce Thornton
The Anti-Chomsky Reader, Peter Collier
Gray Lady Down, William McGowan
Taking Sex Differences Seriously, Steven E. Rhoads
Cold Friday, Whittaker Chambers
The Sleepwalkers, Arthur Koestler
The Third Reich: A New History, Michael Burleigh
Eugene McCarthy, Dominic Sandbrook
Things Worth Fighting for: Collected Writings, Michael Kelly
A Problem from Hell, Samantha Power
Patton: A Genius for War, Carlo D'Este
Free Culture, Lawrence Lessig
The Bushes: Portrait of a Dynasty, Peter Schweizer
Fire from the Sun, John Derbyshire
A Twilight Struggle: American Power and Nicaragua 1977-1990
Robert Kagan
1066 & All That, W. C. Sellar
Occidentalism, Ian Buruma
Nehru: A Biography, Shashi Tharoor
No Wonder They Call It the Real Presence, David Pearson
Life and Fate, Vasily Grossman
A Passion for Books, Harold Rabinowitz
Southern Ladies & Gentlemen, Florence King
Decline and Fall, Evelyn Waugh
Gates of Fire, Steven Pressfield
Dr. Seuss Goes to War, Richard H. Minear
Catholic Intellectuals and Conservative Politics in America, 1950-1985, Patrick Allitt
Booknotes: Stories from American History, Brian Lamb
Booknotes on American Character: People, Politics, and Conflict in American History, Brian Lamb
Booknotes : America's Finest Authors on Reading, Writing, and the Power of Ideas, Brian Lamb
The New Faithful, Colleen Carroll
Rogue State, William C. Triplett II
Hard America, Soft America, Michael Barone
The Radioactive Boy Scout, Ken Silverstein
Jackson Pollock: An American Saga, Steven Naifeh
The Georgetown Ladies' Social Club, C. David Heymann
The French Betrayal of America, Kenneth Timmerman
Library: An Unquiet History, Matthew Battles
A Pound of Paper: Confessions of a Book Addict, John Baxter
Stalin: Breaker of Nations, Robert Conquest
Verdict On Vichy: Power and Prejudice in the Vichy France Regime, Michael Curtis
Dangerous De-Liaisons, Jean-Marie Colombani
A History of the Crusades, Steven Runciman
St. Patrick of Ireland: A Biography, Philip Freeman
Christian Slaves, Muslim Masters, Robert C. Davis
A Terry Teachout Reader, Terry Teachout
The Fall of the Berlin Wall, William F. Buckley
Alger Hiss's Looking-Glass Wars, G. Edward White
Spin Sisters, Myrna Blyth
Rise of the Vulcans, Jim Mann
Presidential Leadership, James Taranto
George Orwell: An Age Like This 1920-1940, George Orwell
The Belief of Catholics, Ronald Arbuthnott Knox
History of the Conquest of Mexico, James Lockhart
Victory, Joseph Conrad
The Great Republic: A History of America, Winston Churchill
History of the English-Speaking Peoples, Winston Churchill
The Second World War, Winston Churchill
Vol. 1, The Gathering Storm
Vol. 2, Their Finest Hour
Vol. 3, The Grand Alliance
Vol. 4, The Hinge of Fate
Vol. 5, Closing the Ring
Vol. 6, Triumph and Tragedy
The Gulag Archipelago, Aleksandr I. Solzhenitsyn
Homage to Catalonia, George Orwell
The Road to Serfdom, F. A. von Hayek
Collected Essays, George Orwell
The Open Society and Its Enemies, Karl Popper
The Abolition of Man, C. S. Lewis
Revolt of the Masses, José Ortega y Gasset
The Constitution of Liberty, F. A. von Hayek
Capitalism and Freedom, Milton Friedman
Modern Times, Paul Johnson
Rationalism in Politics, Michael Oakeshott
Capitalism, Socialism, and Democracy, Joseph A. Schumpeter
Economy and Society, Max Weber
The Origins of Totalitarianism, Hannah Arendt
Black Lamb and Grey Falcon, Rebecca West
Sociobiology, Edward O. Wilson
Centissimus Annus, Pope John Paul II
The Pursuit of the Millennium, Norman Cohn
The Diary of a Young Girl, Anne Frank
The Great Terror, Robert Conquest
Chronicles of Wasted Time, Malcolm Muggeridge
Relativity, Albert Einstein
Witness, Whittaker Chambers
The Structure of Scientific Revolutions, Thomas S. Kuhn
Mere Christianity, C. S. Lewis
The Quest for Community, Robert Nisbet
Encyclopedia Britannica, 11th ed.
Up in the Old Hotel, Joseph Mitchell
The Everlasting Man, G. K. Chesterton
Orthodoxy, G. K. Chesterton
The Liberal Imagination, Lionel Trilling
The Double Helix, James D. Watson
The Feynman Lectures on Physics, Richard Phillips Feynman
Radical Chic and Mau-Mauing the Flak Catchers, Tom Wolfe
The Myth of Sisyphus and Other Essays, Albert Camus
The Unheavenly City, Edward C. Banfield
The Interpretation of Dreams, Sigmund Freud
The Death and Life of Great American Cities, Jane Jacobs
The End of History and the Last Man, Francis ***uyama
Joy of Cooking, Irma S. Rombauer, Marion Rombauer Becker, and Ethan Becker
The Age of Reform, Richard Hofstadter
The General Theory of Employment, Interest and Money, John Maynard Keynes
God & Man at Yale, William F. Buckley Jr.
Selected Essays, T. S. Eliot
Ideas Have Consequences, Richard M. Weaver
The Economy of Cities, Jane Jacobs
The Closing of the American Mind, Allan Bloom
Ethnic America, Thomas Sowell
An American Dilemma, Gunnar Myrdal
An American Dilemma, Vol. 1
An American Dilemma, Vol. 2
Three Case Histories, Sigmund Freud
The Struggle for Europe, Chester Wilmot
Main Currents in American Thought, Vernon Louis Parrington
The Waning of the Middle Ages, Johann Huzinga
Systematic Theology, Wolfhart Pannenberg
Systematic Theology, Vol. 1
Systematic Theology, Vol. 2
Systematic Theology, Vol. 3
The Campaign of the Marne, Sewell Tyng
Tractatus Logico-Philosophicus, Ludwig Wittgenstein
Insight: A Study of Human Understanding, Bernard Lonergan
Being and Time, Martin Heidegger
Democracy and Leadership, Irving Babbitt
The Elements of Style, William Strunk & E. B. White
The Machiavellians, James Burnham
Reflections of a Russian Statesman,
The Hedgehog and the Fox, Isaiah Berlin
Roll, Jordan, Roll, Eugene D. Genovese
The ABC of Reading, Ezra Pound
The Second World War, John Keegan
The Making of Homeric Verse, Milman Parry
The Strange Ride of Rudyard Kipling, Angus Wilson
Scrutiny, F. R. Leavis
The Edge of the Sword, Charles de Gaulle
R. E. Lee, Douglas Southall Freeman
Bureaucracy, Ludwig von Mises
The Seven Storey Mountain, Thomas Merton
Balzac, Stefan Zweig
The Good Society, Walter Lippmann
Silent Spring, Rachel Carson
The Christian Tradition, Jaroslav Pelikan
Strange Defeat, Marc Bloch
Looking Back, Norman Douglas
Mont-Saint-Michel and Chartres, Henry Adams
Poetry and the Age, Randall Jarrell
Love in the Western World, Denis de Rougemont
The Conservative Mind, Russell Kirk
Wealth and Poverty, George Gilder
Battle Cry of Freedom, James M. McPherson
Henry James, Leon Edel
Essays of E. B. White, E. B. White
Speak, Memory, Vladimir Nabokov
The Electric Kool Aid Acid Test, Tom Wolfe
Darwin's Black Box, Michael J. Behe
The Civil War, Shelby Foote
The Way the World Works, Jude Wanniski
To the Finland Station, Edmund Wilson
Civilisation, Kenneth Clark
The Russian Revolution, Richard Pipes
The Idea of History, R. G. Collingwood
The Last Lion, William Manchester
Last Lion: William Spencer Churchill: Vol. 1 Visions of Glory, 1874-1932
Last Lion: William Spencer Churchill: Vol. 2 Alone, 1932-1940
The Starr Report, Kenneth W. Starr
A History of the American People, Paul Johnson
A History of the Jews, Paul Johnson
A History of Christianity, Paul Johnson
Ireland: A Concise History, Paul Johnson
Modern Times, Paul Johnson
Birth of the Modern, Paul Johnson
Disreali, Robert Blake
The Conservative Party, Robert Blake
The Conservative Mind, Russell Kirk
Hitler and Stalin, Alan Bullock
Witness, Whittaker Chambers
Stagecraft, Margaret Thatcher
Democracy in America, Alexis de Tocqueville
Robert Conquest, Reflections of a Ravaged Century
Slouching Toward Gomorrah, Robert Bork
The Guns of August, Barbara W. Tuchman
The Clash of Orthodoxies, Robert George
The Bell Curve, Charles Murray & Richard Herrnstein
Witness to Hope, George Weigel
From the Shadows, Robert Gates
Shakedown, Kenneth Timmerman
Churchill, Roy Jenkins
The Soul of Battle, Victor Davis Hanson
Heaven on Earth, Joshua Muravchik
Bias, Bernard Goldberg
Tommy & Me, Ben Stein
Bobos in Paradise, David Brooks
The Right Man, David Frum
The Seventies, David Frum
Strictly Speaking, Reid Buckley
Tom Wolfe, Hooking Up (read his superb fiction too)
Rohan Gunaratna, Inside al Qaeda
The Death of Outrage, William Bennett
TR: The Last Romantic, H.W. Brands
The Case Against Hillary Clinton, Peggy Noonan
Radical Son, David Horowitz
The Clash of Civilizations and the Remaking of World Order, Samuel P. Huntington
In Defense of Freedom, Frank Meyer
Darwin on Trial, Phillip Johnson
American Jihad, Steve Emerson
Militant Islam Reaches America, Daniel Pipes
Lenin's Tomb, David Remnick
The Rage and the Pride, Oriana Fallaci
The Multiple Identities of the Middle East, Bernard Lewis
Capitalism and Freedom, Milton Friedman
No One Left to Lie To, Christopher Hitchens
Without Reservation, Jeff Benedict
The West and the Rest, Roger Scrunton
The War Against Boys, Christina Hoff Sommers
Michael Barone, The New Americans
At Any Cost, Bill Sammon
Bad Boy, John Brady
Ain't You Glad You Joined the Republicans, John Bachelor
Show Time, Roger Simon
Trail Fever, Michael Lewis
Islam Unveiled, Robert Spencer
America in Black and White, Stephen & Abigail Thernstrom
Losing the Race, John McWhorter
Gore: A Political Life, Bob Zelnick
The End of Racism, Dinesh D'Souza
A Different Drummer, Michael Deaver
America's First Dynasty, Richard Brookhiser
American Sphinx, Joseph Ellis
John Adams, David McCullough
Whittaker Chambers, Sam Tanenhaus
Vaclav Havel, John Keane
Ending the War on Drugs, Dirk Eldredge
The Venona Secrets, Herbert Romerstein & Eric Breindel