Guys (or at least me) usually look for two things, attractiveness and the way they handle that attractiveness. A girl who is too into herself is a huge turnoff. It's shows conceitedness and egotistical nature. A girl who is friendly and attractive can brighten a room. A guy may still have trouble getting her attention or never get it, but there's no denying how appealing a girl like that is.
I'm not a guy but I've always thought that if a girl is drop dead gorgeous then guys might be intimidated by that but for the girls who are just attractive I think if a guy wanted to get to know someone he would.