Source: marvel.wikia.com
4. The Avengers
This is the newest film on this list but I couldn’t NOT put it on here.
The success of The Avengers isn’t just important to the comic book movie industry, but to the film industry as a whole. In the tech world, a common term you might have heard before is disruptive. It means a technology that is so revolutionary, it forces everything around it to change immediately. Don’t believe me that The Avengers disrupted blockbuster cinema? Then I have two words for you: Cinematic. Universe.
True, Iron Man was the start of the MCU, but until 2012, no one knew whether or not the concept would work. Within weeks of the film’s release, The cinematic universe boom began. DC’s Man of Steel became the first chapter of a slate of films, Universal announced a Monster Cinematic Universe (we’ll see if that one ever actually happens), eventually stuff like King Kong and Godzilla even got the same treatment. Without this movie’s success, none of those would have come to fruition.
So, depending on your feelings, feel free to thank/blame The Avengers for the DCEU.

