When comparing between similar levels of economic development, socialism has always provided better quality of life than capitalism. Even in less developed countries, it meets the basic needs of the average person moreso than any capitalist country of similar metrics, without exploitation or imperialism to get there.
Mixed economy. No true capitalist or communist or socialist system has ever existed yet. So whatever is/was the best economy is a mixed economy and whatever is the worst... well, feudalism takes the cake here