i like it when it's a bit longer at the top, not like mohawk or anything though. I also like the look where the front bits (like the bangs) are a little longer and he mousses them up, but too much hair product will look guido-ish.
kinda like the last girl, usually anywhere between covering the forehead and above the shoulders. either straight or wavy; if it's naturally really curly then I'd rather have it either short or straightened.
I like the kinda long/shaggy I don't know what you'd call it with the bangs to the side or in the eyes. The "scene" look I guess is what it's called. I'm not exactly sure. But yeah, medium to longer hair is always good.
too long is to hard to manage, trust me, I tried the long look, my hair got really curly, and was hard to manage, best just to keep it relatively short, like a 1 1/2 or a 2... just make sure you keep it clean, girls really dc about style, they just want a clean head