Being a bit more.. sexually aggressive has attracted me in the past. I don't mean be so aggressive that you freak her out, I mean aggressive in that you are confident in what you're doing and knowing that she wants it. Some girls may like you but keep it at a safe friendship relationship because they don't know that the feeling is mutual. I'm too proud to ask a guy if he's interested, I know a lot of girls are the same. Girls think that it's guys territory to make the first move, and I'm inclined to agree because we're all too pussy to make a move first. Vanity means as much to a girl as ego means to a guy. Nobody wants that bruised.
In that being said, a few months ago I met a guy I found highly attractive, but thought nothing because he acted so casual. It wasn't until I went clubbing with him and he pulled me in for a tongue lashing that I knew he was interested. :P