Which countries are the freest?

It depends. Different people may have different points of view, and also can give more or less value to different things that can imply some level of "freedom". There are many different indexes that sometimes are used for measuring the freedom degree of the world's nations, e.g:

- The Index of Economic Freedom is a well known index, created by The Heritage Foundation and The Wall Street Journal in 1995, that measures economic freedom based on 12 different aspects. It is updated every year.
- The Human Freedom Index is developed by the Cato Institute, a libertarian think tank in the United States. It is a global ranking that uses ranks countries according to their levels of personal, civil and economic freedom.

In any case, it depends on what do you understand by "freedom", and also what you want to compare among the different countries.