Scientific proof Fox is hotter
I posted this on the Dark of the Moon board but thought I'd add it here.
Consider this, Rosie is a Victoria's secret model, now she was probably selected to be one of their models by either a straight woman or a gay man. Straight woman and gay men have weird taste when it comes to female aesthetics, straight women have been brainwashed by the diet industry and womens magazines that thin is in and gay men involved in fashion, especially "high fashion" want to minimise feminine beauty (so as not to distract from the clothes) at the same time pushing some kind of weird social message by promoting androgeny as the pinnacle of beauty.
Most models these days are picked because they look "interesting" or "edgy" in the name of art, in the same way a car crash is "interesting" and "edgy". It has nothing to do with physical beauty or attractiveness.
However casting agents and people like Micheal Bay and the editors of Maxim often get confused between high social status and physical beauty. At the moment Rosie has high social status, that's why she is seen as attractive now when before she was a nobody. Bay proved he has no taste in the second movie when he cast the female decepticon, who looked like a cadaver.
Like someone else said (on the transformers board), the most classically beautiful and feminine transformers girl was the the blonde Australian computer geek girl from the first movie, Rosie's features are not so much masculine but too androgenous, mostly due to her very strong jaw and chin, this makes her less attractive to most straight men because along with her lack of body fat might indicate low estrogen levels and hence low fertility. Megan fox falls somewhere between the two.
Take a look at this article, Fox looks (or looked when younger) more like the girl on the left with high estrogen and Rosie looks like the girl on the right with low estrogen (Rosie has an even stronger more masculine chin).
http://www.newscientist.com/article/dn8251-hormone-levels-predict-attr activeness-of-women.html
Evolution, it explains everything! :)