Deep down, all girls do. It's just that some of them want to be adventurous and thus go after the bad boys when deep inside they do want to be a good guy. And I'm sure there are girls who just solely want good guys. I know this because I am one of those. I don't like getting involved with the bad boy type and I am positive that I am not the only one.
Nice guys are the one's we end up marrying! Haha! Girls just don't want the really sensitive kind of guys that are VERY feminine but of course we sit there and make lists of everything we want in a guy and then one day this guy comes a long and the list just disappears out the window!
So yeah, bad boys can be seen as very attractive to a girl, I'd personally want a bit of both but... Well each to their own! But yes, we like nice guys we're just confusing and end up going for something a little more edgy sometimes? Girls and boys are complicated! A guy will be nice when he meets you and then after you're with him etc, he brings out his other side! The bad guy side! :) I think anyways!
But every guy is nice in their own way! (well most guys), just because a guy acts all hard and tough and gets into some fights doesn't mean he's a bad guy....he can be nice in his own way! For example guys like that can be protective over their girl which is a nice thing! They can be generous too, showering her with gifts or expressing his love from time to time but not overly romantic... Every guy has his nice qualities.