The Last Conformist
Irresistibly Attractive
On quantity, I'd go with Stalin.
On sheer gruesomeness, and acknowledging his limited resources compared to the likes of Stalin or Hitler, Pol Pot is strong candidate. He took a truly wrecked country, and made the previous reign of terror look like paradise. As well as probably killing off a higher proportion of his country's population than anyone else has done. I know it's irrational, but I do feel that slaughtering your own people by the millions is worse than genocidizing strangers.
On sheer gruesomeness, and acknowledging his limited resources compared to the likes of Stalin or Hitler, Pol Pot is strong candidate. He took a truly wrecked country, and made the previous reign of terror look like paradise. As well as probably killing off a higher proportion of his country's population than anyone else has done. I know it's irrational, but I do feel that slaughtering your own people by the millions is worse than genocidizing strangers.