For me it would be personality, always. Not that I don't care about looks, but mostly I don't even feel comfortable in the presence of a very beautiful girl.
Edit:
For the record, there ARE exeptions ofcourse. And with 'not comfortable' I mean 'shy'. And I don't like that.
I know what you're thinking.. Yes, I am inexperienced, but that's because I never wanted a girlfriend in the first place. Maybe sometime.. but anyway, I'll be alright.
