In my perfect world it would be a trilogy. In the first film, Stark wants to start the Avengers with his friends Hank and Jan. The government, i.e. Fury won't sign off on it until they can put a few millitary people on the roster. After Lt. Carol Danvers USAF declines, the Avengers look scrapped. A dejected Tony Stark goes to Norway to meet with their government to make a business deal with Stark Enterprises. While there he comes across Cap's frozen body and takes it to the states to see if Hank can replicate the super soldier syrum. This angers a local nutcase who claims to be the Norse god of thunder.
Back in the US Cap is thawed and to everyone's surprise, he's alive. Fury agrees to fund the Avengers if Cap will agree to be on the team. When he does Thor arrives claiming that no good can come of the US reclaiming its most powerful weapon. Thor only wants peace and sees the Avengers as aggressors.
Meanwhile, the Red Skull, under his alter ego of Dell Rusk is running for president. He plans to rebuild Nazi Germany here in America. And it is up to the Avengers to stop him. Because of this Thor agrees to join the team. Giant-Man, Wasp, Iron Man, Captain America and Thor= The Avengers!
The constant growin up and down messes with Hank's head and he becomes, well, a jackass. He and Jan leave the team after defeating the Skull to work on their marriage. Cap leaves to find himself in this new world while the peaceful Thor returns to Norway, leaving Tony Stark with a bunch of unanswered questions.
In the second movie, Avengers Return, NASA learns of an alien invasion headed for Earth. The Avengers are called into action so Stark recruits, Scott Lang, Wanda Maximoff and Clint Barton. Fury assigns Black Widow to the team as Cap returns to lead the team. Hank and Jan split up and Hank busies himself by working on this new Ultron robot. Stark also lobbys to get hsi attorney, Jennifer Walters on the new team.
The invasion is lead by none other than Kang who has come to Earth looking for the missing cosmic cube that he believes is somewhere in the US. He turns the nation upside down looking for it but in the end the Avengers, Cap, Iron Man, Ant-Man, Hawkeye, Scarlett Witch, Black Widow and She-Hulk stop him.
In the end, Ultro who has been loyal to Hank throughout the movie vanishes.
In the third film, Avengers Dissasembled, the Avengers are called into action to help a trapped astronaut in space. The astronaut is none other than Carol Danvers. She has been zapped by some mysterious rays and when returned to Earth is put in an isolation chamber.
Hank meanwhile has decided that he and Jan should leave the team for good. He brings in his newest invention, The Vision, to take their place.
When the Avengers wake the next morning though, things have changed. Iron Man is no longer dependent on anything syntetic to keep him alive. Cap is in his late 80's. Fury has both eyes, etc. The only person who seems to remember the past is Carol Danvers who was locked in the isolation chamber. When she comes out everyone is calling her Ms. Marvel. Confused she goes to the Avngers for answers and helsp everyone remember who they used to be. It is discovered that Wanda is to blame for the current state of things. The only answer is to kill her, but her friends won't do it.
Later it is discovered that Ultron has found the cosmic cube and has forced Wanda to do what she has done. The Avengers defeat Ultron, reclaim the cube and set everything back to normal. Hawkeye and The Vision are dead, and no one will remember the sacrifices they made.
