(Keeping in mind you asked for our opinions - if anybody wants to argue about it, hey, it's your hair to do with whatever you want.)
I have to join the majority and say long hair. It looks better, and there's just something that gets a guy about a woman with long hair.
I vote for natural. If it's naturally straight, you can't make it look curly without making it look fake. Even naturally curly hair that has been straightened looks... odd. Nothing technically wrong with it, and you do whatever you want with your hair. But it just looks weird.