Now a days it seems that anyone can be an Avenger, looking at you Castle, but there are certain characters that more "Avengery" the guys who pop in your head as classic or mainstays. Obviously Cap, Stark and Thor. However I guess this varies depending on what era you may have grown up with. In your mind who are the Avengers??
For me
Captain America
Thor
Iron-Man
Ant-Man
Wasp
Hulk
She-Hulk
Black Widow
Captain Marvel (Carol)
Black Panther
Vision
Wonderman
Spectrum
Scarlet Witch
Quicksilver
Hawkeye