Both curly and straight hair can be attractive, and there is no one standard of beauty:
Curly hair
Many men find curly hair attractive because of its soft, natural look and how it frames a woman's face. Curly hair can also be seen as a sign of youth.
Straight hair
Long, straight hair is associated with femininity and can be considered one of the most attractive looks for women. Straight hair is also popular because it can be styled in many ways and can look neat and tidy.