Well, 'The Naked and the Dead' by Norman Mailer is a significant World War II war fiction. It shows the brutalities of war and the complex relationships among soldiers. 'For Whom the Bell Tolls' by Ernest Hemingway is set during the Spanish Civil War which was related to World War II. It's about an American fighting for the Republicans. And 'The Longest Day' by Cornelius Ryan is a great fictional account of the D - Day invasion.
One great World War II war fiction book is 'The Book Thief' by Markus Zusak. It tells the story from the perspective of a young girl in Nazi Germany. Another is 'All Quiet on the Western Front' which gives a harrowing look at the war from a soldier's point of view. Also, 'Slaughterhouse - Five' by Kurt Vonnegut is a unique take on the war, with elements of science fiction intertwined.