Recently, several studios have focused on major franchises that have earned billions of dollars. Some of these include:

Peter Jackson's Middle-earth $5.9 billion.

James Bond: $6.8 billion.

Star Wars: $7.6 billion.

JK Rowling's Wizarding World: $8.5 billion.

However, the Marvel Cinematic Universe is the largest movie franchise to date. Marvel owns several series that can stand alone, such as Iron Man, Spider Man, Thor, and Captain America. While these films have been successful in their own right, it is the cross-overs and merged films that have made the MCU so popular.

With ensemble casts for Avengers, Captain America: Civil War, and other MCU movies, fans who are not interested in one superhero will still see the movie to watch their favorite. With 16 movies currently released, and 10 more in various stages of production, the Marvel Cinematic Universe has grossed over $12.6 billion dollars, making it the highest grossing movie franchise.

More Info: en.wikipedia.org