Thanks for tough and honest questions!
One of the best current examples of a "communist" country is Nepal. Nepal is usually communist. What do I mean by "usually?" The communists are usually in power there. When they occassionally lose power nationally, there is a peaceful transfer of power. No authoritarianism. The country is VERY socialist/communist in day to day life. You'll see pictures in people's houses of Marx and Engels (among other famous communists).
One of the best overall examples of communism is the original Mormon settlements in Utah in the 1800s. They were outside the US (at that time) and the world was still unconnected enough that their government was not seen as a threat like (for example) Venezuela or Cuba. The Mormons ran their society as a commonwealth, sharing everything.
Note that I'm neither a mormon nor do I think much of their religious beliefs. But I think if you want to live in a society of people who believe like you do, and you're not forcing people to live there, I have no probleam with that. Such were the mormons back then.
Since the late 1800s the US has taken a VERY hard line against anyone NOT being captalist. As time has gone on, this has compe to mean anyone NOT being capitalist AND accepting that the US is the top of the capitalist pyramid scheme.
Jumping back to Nepal and here is the key to how Nepal stays communist without anyone really noticing. Nepal does not have natural resourse the US is trying to extract, unlike Russia, Venezuela, or Cuba.
Nepal is therefore NOT under massive military and economic sanctions from the US that make normal life almost impossible.
It is not hard to measure the USSR's (Russia was before and after the USSR) and China's success raising people out of poverty. Percentage-wise they are also the best examples.
Somewhere (maybe multiple places) in the thread with Grant I also point out that there is no such thing as a "communist" or "capitalist" country today. ALL countries are a mix. The US has public courts, public armed services, and social security. Cuba and China have private property.
The words "communist" and "socialist" are mostly just used for scaring people in the west who grew up during the cold war (like me) and were massively propagandized to think everything.
The more socialist countries of the west are ALL the countries that are happiest. No exceptions.