When I was in the fourth grade, my first real crush was on a girl who was cute, had money (her father had a well-known car dealership), and smart -- clearly at the top of our class. Now that I'm thirty, I find I'm still attracted to that type -- although money has never had a prominent role. What takes someone from sheer interest to real attraction has been a sense of drive. I admire someone who has interests and goals and pursues them. I've never been interested on girls who I thought were easy or didn't have a life. Even if they don't exactly match with mine. If a girl has a certain physical appeal, shares my values, and is driven -- that's the ticket.
The commonality that I've noticed with all the girls/women I've been attracted to has been a certain waifness -- being small-framed myself (38 S-R suit size), I just feel more comfortable with those I can wrap my arms around. I agree to the theory of attractiveness equals, and would add to that physique equals (not necessarily the same thing), that make a relationship stick longer. After all, have you ever seen an overweight person with a thin person? Rarely.