Masters of Evil in Avengers movie sequel

With Avengers 2 set to be released next year, this poster got me wondering...

Though the Masters of Evil won't be in the upcoming movie, they should be considered as future villains for an Avengers sequel. Which villains would you like to see / should be in the roster to oppose the Avengers.

They're making a Sinister Six movie...why not? Baron Helmut's is probably my favorite.

I was rallying for the Masters of Evil in an Avengers sequel before it was cool. #HipsterShark