[Kyt]

I voted Japan on the basis on Army. Though the Nazis state were responsible for the worst systemmatic atrocities, their army, on the whole weren't.

However, the Imperial Japanese army (and a much much lesser degree the Imperial Navy and Imperial Air Force) was responsible for most of the atrocities carried during the war - against civilians, POWs and fighting soldiers. From Nanking to the Burma Railway, it were the soldiers from the very top to the very bottom who did the raping, the torturing, the killing, and the general mistreatment of everyone.

EDIT: I posted this whilst Spidge was posting the above - so it seems that I was generally right.