Come on, it-ogo, stop playing an Ukrainian-nationalist-wannabe. If we are speaking about the relation to USSR and Stalin you are no less Russian than myself.
Back to the topic question. In my opinion Stalin - is a typical criminal in power. Former bank robber who used the chaos of Revolution to grab the power. He trusted no one and built the entire state mechanism to serve his paranoidal policy. I really think that the harm he caused to my country is comparable with the harm caused by nazi invasion.