Russia's involvement was by far the biggest factor in the allies winning the war and the country with the most casualties by far, so I'm going with them. The sad thing is their leader was as much of an asshole as the German one...
The UK was, at one point, fighting against Nazi Germany and conquered Europe on her own. Also commendable stuff.
The U.S.'s impact on the outcome of the war is waay overrated, too many Hollywood movies make it seem like they won the war on their own and saved Europe, when their enemy the USSR had much more of an impact. Of course, the Europeans were happy to raise the Americans' self-esteem and gladly licked their butts a bit for some much needed money, so all is good.
Japan was pretty interesting, too. My fiancées grandma was trained with bamboo to fight the Americans, lol.
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.
