Soviet Union: 7-20 million deliberately starved to death. [1] 1.5 million people executed during The Great Purge. [2] "Did pretty well".
Cuba: thousands executed for the ideas they held; forced labor camps; and more than 1.2m fled 1959-1993 (about 10% of the current population). "Doing pretty well". Cuba was one of the wealthiest countries in the Americas, before Marxists took over.