Has there ever been a truly socialist country? Even in the USSR and their puppet states, the ruling class had all the power and wealth, the ruling class being the leaders of the communist party, and the workers were terrorized and lived relatively poor lives. The same goes for many other communist countries except maybe Cuba.
The USSR was a socialist society for a little while, but it ultimately degenerated into rule by bureaucracy, as was the case in all of it's periphery states (although most of those were never 'socialist' in the first place, unlike the USSR in its foundational period). But that's not to say there haven't been a lot of examples of genuinely socialist societies throughout the years; the Paris Commune, Revolutionary Catalonia during the Spanish Civil War, and the movements to establish real socialist societies in the eastern bloc in Hungary in 1956, Czechoslovakia (and elsewhere) in 1968, or the May '68 movement in France. Unfortunately the defeat of the German Revolution by none other than the social democrats (working in concert with brutal reactionary thugs) essentially sealed the fate of the USSR because the revolution was confined to one geographic area and strangled from without (by means of economic warfare) and fell from within (with the rise of Stalinism and rule by the bureaucracy).