Girls don't really go for jerk guys... at least I don't. Just a few of the guys I've dated have been rather jerkish to other people.. and when they've been jerkish to me, I've tossed them to the side.
Confidence has something to do with it. And you don't have be to a jerk to have confidence. And while you don't have to spend every waking moment on the girl, giving her some attention doesn't hurt. Otherwise why bother with a girlfriend, huh?
The type of guys I like are the geeky ones.. who're nice and fun to talk to.