World War 1 Books

GERMAN
Arnold Zweig; The Case of Sergeant Grischa (1927) (Russian POW tries to escape from German camp)

Erich Maria Remarque; All Quiet on the Western Front (1927) (WWI classic)
Ernst Junger; Storm of Steel by (war from POV of young German soldier)
Fritz Nagel;

Fritz: The World War I Memoirs of a German Lieutenant

FRENCH
Henri Barbusse; Under Fire (1916) -- "one of most influential of all war novels"; 1001 list
Romain Rolland; Clerambault ( 1920) --1915 Nobelist; author describes this book as "the confession of a free spirit telling its mistakes, its sufferings and its struggles from the midst of the tempist."
Louis-Ferdinand Celine; Journey to the End of the Night (1932) -- Celine's first novel

CZECH
Jaroslav Hasek; The Good Soldier Svejk (1923) -- classic satire

RUSSIAN

Alexandr Solzhenitsin;

August, 1914 (1972) by

Alexandr Solzhenitsin;

August, 1916 (1998) by Alexandr Solzhenitsin

GREEK
Stratis Myrivilis; Life in the Tomb

NONFICTION
Guns of August by Barbara Tuchman
Seven Pillars of Wisdom by T.E. Lawrence--the real Lawrence of Arabia
A World Undone: The Story of the Great War, 1914-1918 (2007) by G.J. Meyer
The Great War and Modern Memory by Paul Fussel--explores the works of many of the writers who memorialized the war; winner of the National Book Award, National Book Critics Circle Award, and named as one of the Modern Library's best nonfiction books of the 20th century
Back to the Front: An Accidental Historian Walks the Trenches of World War I by Stephen O'Shea

BRITISH, AMERICAN, and CANADIAN
Regeneration; The Eye in the Door; The Ghost Road by Pat Barker (Booker prize winning trilogy)
The Enormous Room (1922) by E.E. Cummings (semi-autobiographical account of war protester incarcerated in France)
A Farewell to Arms (1929) by Ernest Hemingway (based on Hemingway's personal experiences as an ambulance driver)
Goodbye to All That: An Autobiography (1929) by Robert Graves
In Parenthesis (1937) by David Jones (one of major works of 20th century poetry)
Johnny Got His Gun (1939) by Dalton Trumbo (classic anti-war novel)
The General (1936) by C.S Forester
Parades End by Ford Maddox Ford (masterpiece about transition from orderly Edwardian age to madness of war)
An Ice Cream War (1982) by William Boyd (war in British and German colonies in East Africa)
Three Soldiers (1923) by John Dos Passos (plight of ordinary enlisted man)
Birds Without Wings (2005) by Louis de Bernieres (Gallipoli--Turkish pov)
The Wars (1977) by Timothy Findley (Canadian soldier in WW I)
Memoirs of an Infantry Officer (1930) by Siegfried Sassoon (based on Sassoon's experiences in the trenches)
Testament of Youth (1933) by Vera Brittain (memoir of a generation)
A Soldier of the Great War (1991) by Mark Helprin (cultured Italian's war experiences in the Tyrol and Sicily)
The Secret Battle (1919) by A.P. Herbert (Gallipoli; praised for its accurate and truthful portrayal of the effects of war on soldiers)
Through the Wheat (1923) by Thomas Boyd (marines in WW I)
Paths of Glory (1935) by Humphrey Cobb (basis for the Stanley Kubrik film)
Wipers: A Soldier's Tale (2009) by Jeff Simmons (digging trenches under no-man's land at Ypres)
Generals Die in Bed (1930) by Charles Yale Harrison (Canadian soldier on the Western front; "no gentle treatise on war)
The Patriot's Progress by Henry Williamson (Harper's called this a masterpiece)
Private 12768: Memoir of a Tommy (1926) by John Jackson
Death of a Hero (1929) by Richard Aldington (Lawrence Durrell called this the best war novel of the era)
To the Last Man (2005) by Jeff Shaara (American experience narrated by historical figures)
5516606::Company K (1935) by William March (series of first hand vignettes by cross-section of soldiers)
Her Privates We (1929) by Frederic Manning (Battle of the Somme; amazon reviewer: "There is no account of World War One that can be compared to this work.")

OTHER
The Penguin Anthology of First World War Stories (2007);  primarily British authors

Sources: All around online groups for several sites such as Librarything & Goodreads