Hey there! Glad to see someone else interested in Stalin, someone whose life was so interesting he became my personal favorite.

I am an undergraduate student who is focused on Soviet studies and post-USSR Russian development. I am absolutely no expert (nothing even close) but I can tell you that I have done quite a bit of research on Stalin. To quickly answer your question, there is really no great video documentary on him that I would recommend. A lot of this is my personal opinion, but I believe most of the films I have watched only dance around concepts historians continue to debate to this day. This includes his drunkard father's treatment of his mother and him -- his relationship with trotsky and how he betrayed him -- and how much influence his inherent distaste for religion had on his pragmatic/earthy perception on human life.

I would however recommend quite a few novels, as I find that true understanding of complex historical figures (especially one such as Stalin) can only be found in peer-reviewed research. If you are interested please Pm me as I don't have access to them at this moment.

Some basic things you can be sure of:

• Stalin was, amongst other things, an excellent organizer and highly intelligent.
• He utilized some of the first known applications of "photoshop" to remove political opponents from photographs of Lenin. He targeted people such as trotsky in order to remove any boost in popularity they would gain by being a known ally of the man. (Post-Romanov Russians LOVED Lenin, and his popularity was used to boost Stalin's ascension to power)
• Stalin did not trust very many people belonging to the 'intelligentsia' such as scientists, lawyers, and economists. This stemmed from his paranoia regarding someone else overthrowing him or even just undermining his plans.
• That very paranoia is what led to the Great Purge, which is what I believe is what you are referring to, wherein Stalin utilized the CHEKA (secret police) to kill/torture/kidnap/blackmail any 'threats' to his regime.
• His father was a drunkard and did beat young Joseph quite regularly, causing permanent damage to one arm which is why Stalin stands prominently to one side during most of his speeches and photographs. ** Historians will argue that this abuse caused him to seek authoritative power in order to not be an 'little guy' again, but this is why I caution away from video documentaries because they make a lot of shaky claims.
• Stalin's purges targeted so many highly educated people that the Soviet Union faced years of scientific lag, which added to the concept of Destalinization where the Soviet premiers who followed Stalin had to essentially clean up his mess.

Hope this helps, but please feel free to contact me. I love this stuff!