Netflix began as a DVD-by-mail service; today, it is the most prolific production studio in the world. They produce more original content in a month than old-school studios produced in a year.
Often the underdog, FX has been the most consistently brilliant studio of the last fifteen years. Under John Landgraf (dubbed the "Mayor of TV"), FX mastered the "limited series" long before it was trendy.
Having acquired the historic MGM library (James Bond, Rocky), Amazon has shifted from a complementary service to a theatrical player.