Re: Megan Fox or Rosie Huntington Whitely?
If I judge by the looks, I choose Megan. I am no fan of how she looks nowadays, it's totally unattractive, but in both TF movies, she looked AMAZING, especially in the first, while Rosie is nothing special and I don't really like her face.
In terms of acting (although in this type of movie, you don't need amazing skills), I'd choose Rosie. She was alright aka better than Fox.
So there you go, it's a TIE for me, but I couldn't care too much about either of them, it's the robots that matter most to me.