I don't always tend to go for the 'traditionally' attractive girl, I look more for subtle beauty, and forms of perfection (Its hard to explain, but basically I find some girls more attractive than others would say they are, and some girls less attractive than people would say.)
Also, what I know of the person's personality will affect how I see their looks, the two are linked for me.
So in answer to OPs question, I have quite a large amount of people I would be willing to give it go with, but I do have standards, and I don't just throw myself at anyone.
(P.S. On a good day, I consider myself plain. On a bad day, I consider myself ugly. I just hope the girl sees my good points, not my bad.)