The Edelweiss Pirates series is probably my favourite WW2 books. Like no other it covers the life of ordinary German teenagers during WW2 who hated Hitler, The Nazi's and the war. But they loved Germany, they just wanted fun.
The chapters in the concentration camp are the best I have read, it brought it to life, a 13 year old jewish boy struggling to understand. It made me cry in some parts, and laugh in others. A truly remarkable novel.