I definitely like longer hair, curly/wavy is best, or at least with some volume. More towards the messy side is better, actually for me it's hard to imagine a style that's too messy or uncontrolled. There's something that bugs me about when guys' hair looks styled, especially if it's shorter ('cause the less hair someone has the less need there is to style it). But everyone's different, and different things suit different people... go with whatever makes you feel the most comfortable, and confident with yourself, that's always best.
Well that depends. Personally I like longer curly hair but it has to look a little bit messy like you just woke up. When it comes to this, most girls prefer something in between. A bit messy, but still controlled. Fashion magazines prefer straight hair, and you know fashion is critical for girls. But in any way you wear it, as long as you feel confident no girl can resist you. Good luck.