Captain America

Despite not being a founding member, Captain America has become synonymous with the idea of the Avengers. He makes up one part of the team's "Holy Trinity" along with Iron Man and Thor, and if they represent the team's brains and muscles, respectively, then Cap is most certainly its heart. His conscience, honed by the sensibilities of the WWII-era, has often been the moral compass for the team, putting him at odds with his friends as much as his enemies. But his natural ability for leadership has cemented his status as one of the best leaders the team has ever seen, whether inspiring confidence in demoralized members or leading the charge into a fight with the signature battle cry "Avengers Assemble!"