My actual choice was betwwen Hitler and Pol Pot and here I used mere arithmetic as a criterion for my choice. Correct me if I'm wrong but it was Pol pot who is responsible for death of 1/4 jf the whole Cambodia's population. No bloody dictator on Earth was able to achieve such a rate of murderousness as to his own county's population.
So, my choice is Pol Pot.
Okay. But Francisco Lopez actions lead to the deaths of 83% of his country. While not as intentinal as Pol Pot, this was one nasty figure.