Why yes, Stalin was a good guy when he was a vital ally from late 1941 to late 1944. He changed back when we began to realize that, in winning the Eastern Front, the Red Army was going to occupy the eastern half of Europe and Stalin might not want to give it back.

Hollywood even made war movies depicting the heroic Soviet stand against the Nazi invaders during that period. Those movies didn't get run on TV much in the 50s and 60s like the other war movies, though.

My real point was that Stalin's career set an unparalleled low in the 30s when he wiped out all of his potential rivals including most of the senior army officers, the bulk of the small but growing Soviet middle class and farmers who had actually owned any land. The numbers of people killed were reported in the millions. That period defined the style he was going to use the control the Soviet Union through out his career.