All Quiet on the Western Front, by Erich Maria Remarque (HC, 1930, $4, which is 1/3 the internet price)
I remember reading this in high school, and what an effect it had on me. Weeks afterward I was still thinking about it. The weird part was that this was in 1971, while US soldiers were still fighting in Vietnam. You would have thought a book about a long ago war wouldn't have mattered much. But it did. Was it that it is a masterpiece? Or because my class was to young to be part of the draft? Or because seeing pictures on the TV screen seemed too unreal? I have no answer. I just remember it did, and so much so that I have avoided re-reading it ever since.
The book was originally published in Germany in 1929. The American version also came out in 1929. Between its first American edition (June, 1929), and this edition (February, 1930), nineteen editions had been published! Wow!
Look for this in the classics section.