Funny, the number that Hitler "killed" keeps going up. The last reliable number I heard was 20 million, and that's counting combat deaths.
Meanwhile, communism was responsible for the deaths of more than 100 million NON-combatants; around 40 million is on the USSR's Stalin, and around 60 million is on China's Mao, with numerous other countries making up several million. (Including Cuba's Castro, as well his chief torturer/executioner of homosexuals, Che Guevara, the guy liberals hail as a hero).