Going just by the body count, Mao in China wins hands down, followed by Stalin, Hitler was a distant 3rd. Among the also rans Pol Pot in Cambodia. This is just recent history, the last 100 years.
To Webferret. Sorry but Vlad never set foot in Austria or Germany. Transylvania never was part of either country and you also seem to be the only one who knows all the gruesome details of Hitlers love life.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.