Would you be more interested in approaching a girl who's pretty but doesn't really wear makeup and dresses kinda average or a girl who's not that pretty but looks more put-together, wearing makeup and dressing trendy?
DEFINITELY the girl who is pretty but doesn't ware much make up. This simply means she has a natural beauty and that lasts longer then the makeup for the night. Again do what you have to do to make it work but makeup caked all over your face isn't going to make me want to approach you and tare your clothes off that night. Believe me, most of us guys don't care if you are "dressing trendy". I know it's what a lot of girls think about all the time because they need to be validated but I want YOU, not your validation. Best of luck ;-)
I'll definitely pretty but bare. I don't go for girls who are all dressed up regardless and I prefer no makeup. So the fact that the one not wearing the makeup and dressed plain (which is what I prefer anyway) happens to be prettier in this scenario just cinches the deal.
I'd say make-up and clothing are waay different categories, but anyday of the week I'd take the girl with less make-up.
Even if she was a little bit less pretty than the make up girl, I would still choose her. Make up is just fake is all, sure a little is nice, and on special occasions it never hurts, but still. less is more.