A Soldier of the Great War by Mark Helprin (I never tire of recommending this book.)
Cross of Iron by Willie Heinrich
Goodbye to Some by Gordon Forbes (Navy patrol bombers in the SW Pacific. There was a reason they didn't drill procedures for losing an engine on takeoff.)
The Last Squadron by Gerd Gaiser (Things were pretty good for the Luftwaffe fighter squadrons until they had to try to hold back the tide coming out of Willow Run and Santa Monica.)
And Quiet Flows the Don by Sholokhov

The man-eater hunting books by Jim Corbett aren't fiction but they are great. I think it was Robert Thompson maybe who said if you want to understand what it is like to live where terrorists reign, read Jim Corbett's books.