Reporters without Borders (RSF) recently published its 2017 World Press Freedom Index that provides a ranking of press freedom for 180 countries around the world. The methodology is based on responses to a questionnaire that they annually conduct. RSF has been producing this index since 2002. Unfortunately, 2017 is not a good year and shows how things are getting worse in many for the press overall.
The color-coded map below shows the encoding. The darker the color, the worst is the ranking. The Scandinavian countries and a few other European countries (in tan color) are in the top of the list as having the most press freedom. USA is ranked 43 and with the current administration, I presume things are going to get worst. Many of the Asian and African countries (in red and black) are the worst with the least press freedom. Egypt, Saudi Arabia, and China are among the worst (black).
The RSF website provides the detail for its methodology including the questionnaire. You can support RSF and its work by donating money on its site.