Robert Duvall played Stalin in a movie that is shown on youtube. Pretty good-all the cast of characters are there:
Stalin of course, Lenin, Trotsky, Kirov, Beria, Bukharin, and many more.
I was skeptical going in, but I think Duvall did a fine job.
Here is the link to the movie.
Of course, the movie tries to paint the revolutionaries Stalin killed in a sympathetic light, but the fact is, they were all as brutal as he was.