Real Name: Janet Van Dyne 

First Appearance: Tales to Astonish No. 44 (June, 1963)

Powers: Like husband Henry Pym (Ant-Man, et al.), The Wasp can manipulate he size, shrinking to the level of the insects or growing to a height many times that of a normal human being. She can also fly and shoot energy blasts. 

Hero or Villain: The often tiny heroine has had to put up with a lot of Pym's problems, but has stayed uncorrupted throughout.

Why: She's one of the founding members of the team, a former Chairwoman and it might be nice to show that the Avengers have included more than just one female (the film's Black Widow) through the years.