Slaughterhouse-Five is an excellent book by Kurt Vonnegut that blends science fiction with true accounts of war. The book has an anti-war feel to it; the horror and mass killing that exists in war is part of the main background of the story.
Possibly one of Vonnegut's most famous novels, Slaughterhouse-Five is a very quick read. I'm usually a fan of longer books but this ~200 page book is great because Vonnegut's style is amazing and the story doesn't need an epic amount of pages to get the point across.
I highly recommend this book to anyone looking for a great story with interesting characters and a unique writing style. Vonnegut is one of America's greatest writers and deserves to be recognized and read.