Steve Rogers/Captain America: If you ever needed a leader and wanted to make sure your every directive was followed, you employ Steve Rogers to get the job done. Rogers was the first Avenger and the last Avenger and the team’s heart and soul (and mom), no matter the roster.
Bruce Banner/The Hulk: Bruce Banner brings not only his vast genius intellect to the fight, but also his green angry alter ego Hulk, who is equal parts mad as he is cunning and destructive. The madder Hulk gets, the better the outcome for the Avengers.
Tony Stark/Iron Man: Much like Banner, Tony Stark brings his intellect to the fight and usually other toys to ensure that the Avengers will win. Beyond that, Stark provides a place for the Avengers to stay and upgrades for every team member. Think of him as the dad of the team as well as the brains of the organization.
Luke Cage: Now that Netflix has brought some of the more background Marvel characters to the forefront with excellent (but canceled) TV shows, Luke Cage has a spotlight on him that showcases his invaluable contributions. Cage is virtually indestructible with super strength to match. The Hero for Hire hasn’t joined the Avengers in the Marvel Cinematic Universe just yet, but know that when he does, it will be worth the wait.
John Walker/U.S. Agent: An alternate version of Captain America, U.S. Agent is a bad dude. Receiving his super strength from the Power Broker, John Walker has gone against Captain America and won as well as joined the Avengers and its derivatives such as Norman Osborne’s Dark Avengers. Walker once worked for the Commission on Super Human Activities and has taken up the Captain America mantle in the past.