Looking back historically, Audrey Hepburn or Grace Kelly: both, in their different way the epitome of feminine class.
Then again, having seen Gravity, and thinking of someone who's even remotely age-appropriate, I would kill for Sandra Bullock's figure, and her ability to play comedy, tragedy and action at an Oscar-winning/nominated level, while still remaining an intelligent, seemingly grounded, witty woman. If only ...
And Tina Fey ... seriously, who wouldn't want to be that cute and that funny?