This is a tough question to answer, the obvious is to just look at who won, America, Russia, China and the British Empire beat Germany, Italy and Japan, therefor Britain, America, Russia and China must have the best armies, yet this in itself is too simplistic. Lets consider what we know as fact.
America had the largest Industrial base of any of the nations, therefore could produce weapons at a vastly increased rate.
Germany had the best technology, at least at the beginning of the war as they had time and space for preparation and came out with some of the most inovative weapons of the war.
Russia could afford to lose people wholesale and not notice and retreat to allow other factors, including weather to take its toll on the enemy.
Britain had a vast Empire, with access to oil, minerals, food and vast quantities of men to help spread the load.
Japan had been fighting for years against Russia and China and bouyed by these successes had become truly hardcore death or glory fighters.
China, had a huge country, making enemies need to spread out to gain effective control.
Italy.... well Italy had nice uniforms.
The number of troops lost also doesn't tell you much as with all these things equipment, air power and battle tactics take a part in the number of deaths sustained, as does front-line medical assistance and ancillary medical care. With every nation involved in the war i can think of instances where they fought hard and against immesurable odds, in attack and defence.
Personally, i don't think any was the best army, all had good and bad points, all had victories and defeats, all i can say is which army i'd want backing me in a fight and that comes down to personal preference, for sheer tenacity, ability and force of spirit i'd choose the British Army every time.







