It is very hard to cite a 'successful' Communist economy when every single one has been attacked militarily and undermined by US-NATO forces. Nonetheless some have survived. Most have not.
Yugoslavia was a communist country founded by communist partisans who resisted Nazi occupiers during the second world war. Yugoslavia prospered until after the Soviet bloc collapsed. As a result Yugoslavia was isolated and was pulled apart by subversion and military aggression by US-NATO.
The Democratic Peoples' Republic of Korea (DPRK - also known as 'North Korea') survived the most ferocious bombardment (per square kilometer) endured by any country in history during the 1950-1953 United States war against Korea. Given that this is even attested to by US Airforce General Curtis Le May, there can be no doubt that this was a genocidal war. In spite of that, the North Koreans and their Chinese allies were able to fight the United States and its allies to a stand-still.
In Greece during the Second World War the Greek Communist-led ELAS partisans administered most of the country that they had liberated from the Nazi occupiers and their collaborators. In spite of the war and conflict, these regions were very prosperous. Unfortunately because of the infamous 'percentages agreement' between Stalin and Churchill, in October 1944, the Greek ELAS partisans were tricked by the Greek Communist Party (KKE) into disarming, whilst former collaborators were rearmed by the British. As a consequence of this the liberated zones were conquered.
Most post-war countries could be described as socialist, or at least command economies, with all resources and services nationalised. Gradually they have been privatised, with disempowering effects using the excuse of economic liberalism. Syria is socialist and worked very well before being attacked by US-NATO. Cuba has a completely socialist economy and has faced total hostility and continous sanctions and propaganda from the United States, yet has managed to survive for 60 years, even when the oil subsidies from the soviet union were cut off it still managed to keep its economy going. They supplied doctors to work in lots of third world countries in Brazil, Venezuela, Africa. Every Cuban has free medical and hospital services.
Venezuela is yet another case where the capitalists simply won't permit any other form of economy.