Psychopathic mass murderer aside, Stalin survived so long by getting good information. He drank vodka with his senior comrades, while he actually drank water from a vodka bottle - getting them drunk to reveal any disgruntled feelings. He was also a dedicated psychopath, allowing his son to be executed for rape rather than sparing him as his son.Hitmouse, I'd heard that about Animal Farm, but hadn't read the history.
I've also heard Death of Stalin is good. Incidentally, the comically overblown medals on Zhukov's uniform actually slightly underplays how many he had.
Hope the 'Death of Stalin' accurately portrays how darkly psychotic and calculating he was. Chilling..