I think あなた chose quite a nice 質問 to ask there. :) I like Kristen because one can see she really puts a lot of effort into the way she acts on-screen. Honestly, she is a brilliant actress. When I watched her, I was so moved at certain parts. I think if I ever had to go into acting, I'd definitely ask her for her advice. She played the part of Bella spectacularly.
Robert is amazing. Not only is he attractive, but he's a magnificant actor. He played Edward with such elegance that it was hard not to like him. I think neither him nor Kristen are just pretty faces. They are blessed with loads of talent.
I like them both because they truly deserved their roles and made them their own.