Both?
Free market is good in some sectors, socialism in others. Mix of those is best for most, extreme of either to a few (those who have power).
It's actually always a hybrid. Many of liberal states have lists of socially important goods with State controlled prices. There are also such things as antimonopoly committee etc.
"Planning and market forces are not the essential difference between socialism and capitalism. A planned economy is not the definition of socialism, because there is planning under capitalism; the market economy happens under socialism, too. Planning and market forces are both ways of controlling economic activity".
- Deng Xiaoping in 1984