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.

USA helped a decent amount against Germany.  However, Russia took a huge beating at first before they could turn things around.  US helped a lot with supplies, troops, air power, etc in Europe.  I wouldn't say their contributions are vastly overrated (maybe in some Hollywood films).  Most documentaries and History Channel specials make it obviously clear that Russia helped the most against Germany.  US contributions against Japan are probably the most with England, Australia, New Zealand helping a decent amount also against Japan.

 "The origins of the T-34 stretched back to early 1930s, when Red Army planners supported a prototype tank designed by the American J. Walter Christie, its innovative suspension siring a series of Soviet BTs, or "Fast Tanks."  Industrial legend has it that Christie's designs embodied most of the advances that later made the T-34 such a superior machine, but Soviet engineers vastly improved everything."  - Soul of the Sword 

Just thought to throw the last paragraph out there.  While the T-34 can't be entirely credited to J. Walter Christie he did show them in the right direction.  Russians are always good at copying, stealing, and improving on other countries weapon designs (airplanes, tanks, etc). 

I didn't want to imply that the US didn't have a big impact, which it did, especially in the Pacific front. Just that so many movies and games make it seemed like it was US v everything. Of course, someone who's very informed of WWII as you is not going to have that image, I'm talking about people who's only source of information in this matter are movies, games, etc.

To be perfectly honest I'm not a big expert in WWII (though I know how it played out in general terms and what role the parts played), and especially don't know much about the weapons used during the war, so I didn't know about the T-34, thanks for that. However, I have the feeling that, despite people making it seem like the US and USSR were equal powers during the cold war, the American economy and engineering was always much better (despite Russia having more nuclear weapons, launching to space first, etc), so you're probably right.

I was actually trying to find an original weapon made by the Russians and I came up with the AK-47.  After looking at the Wiki page on the AK-47 it can be pulled from there that they really were just copying the assault rifle idea mainly from Germany with their StG44.  Since the Russians had plenty of experience towards the end of the war with Germany infantry being equipped with StG44 they obviously saw the value in the assault rifle.  Anyways, the AK-47 was and still is an amazing gun and has proven reliability.  I am sure there are plenty of original weapons ideas that the Russians have come up with but I just can't find any that are completely original.  However, it can be said that most weapons are just improvements based off of previous weapons. 

i don't think the UK would have survived the germans without canada,usa,aus etc

so its a funny old game indeed

They supplied the germans with raw materials, money etc so thet they wouldnt invade them

lots of countries supported the Nazis but they don't like to bring it up for some reason,

just keeping england and the usa as the bad boys is so much easier :P

pretty storng opinoin there (i agree not many people will vote for Albion)

The English and US did well in my opinion the English more so but if it werent for Russia GB was a gonna because America didnt come in till 41

Even though USA didn't join the war till late 41 they still provided the Allies with a lot of supplies.  One interesting fact was that Hitler didn't have to declare war on USA.  He did since he felt they wouldn't be a factor till after Russia was taken down.  The agreement between Japan and Germany meant that they only had to declare war if another country attacked them not them attacking another country.  So technically, Germany didn't have to declare war against the USA but I am sure USA would eventually declare war if Germany hadn't.