Speculative fiction is one of the most popular realms to both write and read, and science-fiction films have made tens of billions of dollars at the box office. In fact, eight of the top 10 highest-grossing films of all time have a sci-fi leans to them, whether it a film from the Marvel Cinematic Universe, China's animated fantasy Ne Zha 2, or one of the entries in James Cameron's Avatar franchise. Two of the three Avatar films — 2009's initial release and its follow-up Avatar: The Way of Water — are first and third on the best-grossing list; but even then, they're still not Cameron's best movie.