Jean Paul II
The historical experience of socialist countries has sadly demonstrated that collectivism does not do away with alienation but rather increases it, adding to it a lack of basic necessities and economic inefficiency.
Pope John Paul II
Piłsudski as he was in control of the Socialist Party. He influenced many people but, arguably, wasn't the most effective leader as, upon his death, he hadn't met many of his objectives.
Yes I should write in Pilsudski to this poll instead one of modern socialist "leaders". HE was definitely one of the most influential socialists in Polish lands.
However he had no similar power like Stalin or Hitler. I'm not a fun of Pilsudki but he doesn't deserve to be mentioned in this company.
Definatly Stalin, he had most influence on all from that list. During war and after the war
On other hand, Hitler's rule was shorter but more intensive.