Most Helpful Guy
I think they're both equally attractive.
The blond girl's picture has better lighting, but is overly cropped, and because of that almost 1/8th of her face is not showing. Her upper canines are a bit prominent, but her jawline is very narrow and feminine. Her face might be more symmetrical, but the cropping effect gets in the way of confirming that.
The brunette is showing most of her face, but the lighting isn't as good, leading to the prominent shadows underneath her cheek bones. She also has some crowding in her front top teeth (the top right central incisor is tilted backwards slightly). Her face is also at least almost exactly symmetrical, which brings me to the flowers: They're covering her chin and most of her jaw, so I can't tell for sure. They are very distracting, but nice. They also cover her chin, so I can't tell if she has a cleft chin or not. Nothing wrong with that; just putting it out there.
Bottom line: they're both young, and very attractive physically. They have some features some people would consider as "imperfections", but I think these are actually beautifying features.
Most Helpful Girl
Blonde.. Because I only like blue or green eyed girls, with light overall featires