Theres one thing both these countries have in common about the WW2- they both joined the war only after beong attacked by the bad guys. However, Russia had more impact defeating the Germans in their homeland before invading Germany and capturing Berlin. Also, it was because of the Red Army which had caused Hitler to commit suicide.
Over 80% of Hitlers armies died on the Russian front. The majority of Hitlers best troops were used for the invasions of Russia. Russian soldiers had smash through German lines and had taken Berlin. Over 20 million Soviet lives were lost. The Soviets had liberated Aushwitz. Like Joseph Stalin had once said: "America provided the money. Britain provided the time. Russia provided the blood.
You cannot ignore that Hitler's early success in the war was largely due to the resources provided by the Soviets. The Red Army was not in good condition, and their only advantage was sheer numbers. Unlike the Soviets who supported the Axis of Evil prior to Hitler's betrayal, before Pearl Harbor the US contributed to the allies' victory off book; our fighter pilots fought within the Royal Air-force, as well as the Flying Tigers on the Asian Front. WWII did not just engulf Europe, it engulfed the world. The Soviets focused only on Nazi Germany, and nearly lost. The US forced the Japanese to surrender, and helped overthrow Adolf Hitler. Berlin fell because the US was pressing Germany from the west while the Soviets pressed them from the east; simply because the Soviets arrived in Berlin first, does not make the victory solely theirs. Unlike the Soviets, the US liberated France, and contributed to many victories across Europe. The soviets simply fought the Nazis in the East, while the US fought them in the North, West, and South.