one of the scariest times to be alive must've been in the months after the nazis invaded the soviet union with the largest army amassed in human history, 3.8 million troops, and advancing without seemingly any hope of being stopped. imagine following the news during that time 
and then imagine hearing about their advance being halted by the onset of winter, right on the edges of moscow, while leningrad was besieged. and the relief felt when finally the nazis faced their first major defeat in stalingrad, an entire army group annihilated by soviet troops
they fought over every street, every house, every room, as if the fate of the world depended on it, because it did. and the nazi menace, which had rolled over belgium, the netherlands, france and other countries with ease, was halted then and there. truly awe-inspiring heroism
their defeat in stalingrad, which wiped out an army group of over a million, including their most elite troops, shook them to the core. they saw themselves as ubermenschen, super-humans, who could easily defeat the backward, inferior judeo-slav race, but instead were destroyed
I believe the shock of this, which shattered the core of their depraved nazi ideology, had as much as if not a greater impact than the t-34 tanks, bc it robbed the nazis of their false sense of invincibility, it broke their morale. after stalingrad they were terrified
as the red army pushed back the nazis, they reached the hell on earth they had created in the concentration camps, factories of death, torture and destruction of jews, romani, homosexuals, communists. see this thread:
then, closing in on him, they forced hitler, the fuhrer of the thousand-year reich, to take a gun, point it at his ubermensch head, and pull the trigger, splattering his brains into a million pieces. then they gathered all the nazi banners, and did this:
and what better way to end this thread than with woodie guthrie's ode to lyudmila pavlichenko, the soviet sniper who single-handedly took down more than 300 nazis. "they are not men, they are fascists"
for anyone who wants to read some moving depictions and first-hand accounts of the war on the eastern front, check out the work of soviet war correspondents ilya ehrenburg and vasily grossman, particularly ehrenburg's "the tempering of russia" and these works by grossman:
also when I was a kid I used to stay up nights watching the discovery channel and they had some great shows (time team ftw!). "battlefield" was pretty good on WW2. here's the episode they had on stalingrad and there are eps on the entire war on youtube
