Well, in my opinion, the answers to your question are various from person to person, because it is absolutely subjective you know? From my point of view, a girl with brown hair and blue eyes is very charming and gorgeous, oh, just my type. And a lot of people around me like that kind of girls. However, Asian people would regard it less attractive than their Asian counterparts. So, this is it.
Well, generally speaking, most boys like girl with brown hair and blue eyes, especially Asian boys. Brown hair always presents fantasy and amazing. When you stand with sunlight, your brown will reflect wonderful and bright color which becomes you an angel and can make people feel peaceful. A pair of blue eyes makes you much sexy and beautiful. A recently study showed that 62% boys like girls with brown hair and blue eyes. However, different people have different views. So it all depends on the boy that you care about.
Generally speaking, the anwser is uncertain, it various from person to person. For example, in Asia , for the most part guys is prefer the straight black hair and black eyes to others, which can give them a feeling of quiet and tender. However, guys in Europe hold a different view, girls with golden hair and blue eyes seem to be more attractive for them, because of the enthusiasm they can feel from the girls. Neverthless, as far as i am concerned, primary impression is not the most important for a girl. Because your real fascination is just expressing by getting along with a guy. And i'm sure the guy who meet you and fall in love with you in destiny is not fond of what you look like, but what you really have inside. So you are so beautiful in someone's eyes no matter what kind of hair and eyes you have.