Some of these are kinda odd. The Austrians don't really deserve to be on that list IMO. They were vicious bastards sure, but not even up there so far as states go.
Meanwhile various Chinese dynasties easily eclipse minor states like Bulgaria (also ? as to why they are there). And Germany only existed for like 30 years.
Meanwhile some (France, the US, the UK, etc.) definitely committed evil actions, but also had good points. That's not to say those evil actions were somehow justified or forgiven, just that if we are to consider the truly the most "evil" (not really sure what that should mean really) then those would reduce the total evil of those. So...I'll vote other. The Mongols or the Macedonians are my pick from those presented, with Rome right up there.