I have a question: why are people suggesting the hottest actresses they can find for Madame Masque? Looks aren't going to be that important, seeing that she'll be BEHIND A MASK!
I say, if they were to put Madame Masque in the third film, get an acclaimed character actress to play the role rather than some hottie-of-the-month, even if they have to skew a little older to find someone with the acting chops to pull it off.