WWII Casualties (KIA/MIA Military only. All figures approximate):
Soviet Union: 10,700,000
Germany: 5,533,000
China: 3,800,000
Japan: 2,120,000
Portuguese Timor: 500,000
Yugoslavia: 446,000
USA: 416,800
The Soviet Union definitely got the "Badass Trophy" with 13.71% of its total population...