11. Guardians Of The Galaxy
It is the first installment of the Guardians of The Galaxy series. This one has an entirely different plot and different characters. However, this one encompasses the most important regarding the Avengers Infinity war and Endgame. Thanos was first shown in this movie. Apart from that the power of the Infinity stones was first shown in this one.
12. Guardians Of The Galaxy Vol. 2
Peter Quill and the other guardians continue their space adventures in this one. Quill finds out that he is half human and half cosmic.
13. Avengers: Age of Ultron
Ultron, a Robot with artificial intelligence realizes that humans possess a serious threat to the universe, so he decided to wipe out all of them. However, the Avengers stop him.
The film showed how Scott Lang, a thief became the Ant-Man and helped a doctor to protect his technology.
15. Captain America: Civil War
During the war against Ultron, the city conceded huge damage to life. The government decides to certify the superheroes. Some of the superheroes agree to the terms of the Govt. while others rebel. This one introduces Black Panther and Spiderman to the MCU movies.