Re: Characters you'd like to see in future Avengers movies?
In no particular order, the Avengers and Avenger villains I absolutely *must* see by no later than Avengers 3:
Giant-Man (I've never been sold on Hank as Ant-Man anyway; it lessens Jan's role when you have two micro-heroes. I'd rather see Wasp as the micro and Hank as the macro)
Ms. --er, Captain Marvel (or whatever Carol goes by these days)
the original Mar-Vell and/or Genis-Vell
Kang the Conqueror
MODOK and AIM
a good incarnation of the MOE (Zemo, Enchantress, Skurge, Klaw, Whirlwind, Goliath, Songbird, Creed & Titania)
THE COTTON AVENGERS
...They move like slick cotton on oil.