I give Uncle Joe the edge cause Hitler was batshit insane with rage.
I'm sure that makes no sense in and of itself, so here's the slightly longer version:
Everything Hitler did post WWI was fueled by his own rage at having lost that war. His mind snapped and with his gift at speaking was able to whip up enough support in Germany, who's people we're in bad shape already due to the Treaty of Versailles, that people got behind him. Then, predictably, after gaining power his rage led to all of his atrocities. Through it all, even though his rage blinded him, he honestly did want what was best for Germany.
Uncle Joe on the other hand, that motherfucker was just ruthless. That dude just wanted his way, and killed anyone that disagreed or told him what he wanted was against the laws of physics. He wasn't fueled by rage, only his paranoia. I honestly don't think he gave a shit about Russia, the USSR, communism, or any living thing on the planet. He just wanted power.
Hitler always struck me as a deranged rabid animal while Stalin gives me the impression of evil with a face.