oliveira8 said:
You know, I was about to say language, but accent is a better answer. Let's go with that.
As for villains, history has a lot to do with it. Soviet Union versus the "West" during the cold war, Germany versus a lot of people during the world wars, Japan versus the rest of East Asia and the US during WWII, the British Empire versus the rest of the world during imperialism, France versus the rest of Europe during the Napoleonic years, the Romans versus "barbarians," Persians versus Greeks, etc.
You can go on and on about it, but basically every society has a history, and that history includes villains. For western societies in the last fifty years, the most powerful contemporary villain is the Soviet Union. Hence, Russians are the awesome... I mean villainous.