Well that absolutely depends. Attraction comes from lots of locations. If I think back to all the times I have felt attraction enough to both dating or trying to date. I have a few different patterns
Raw absolute lust. My one ex and I saw each other and immediately started making out. Very strange level of sexual intensity. This was a fireball of a relationship that lasted a very short time. Physically she would not be considered attractive by the masses. A little butch with a lot of cute.
Our ex was flirty and cute. A really skilled flirter. Her intelligence was above par so she immediately caught my attention. In her, I was attracted to the facade of this initial personality. (physically she is nice too) If I had met her "real" personality first. I likely wouldn't have been interested at all.
I am currently very attracted to SJ. This pattern was forced to be one of intelligence and friendship. This is a new one for me as I have never had a friendship transition into a relationship. The attraction in this one came from getting to know her personality, quirks and intelligence. She attracted me in the same way Pengrah did the first time we met. Although with Pengrah I was able to get physical very very quickly.
Angelina Jolie, if we are talking stars, is the type of woman I like. Now I know 70% of the population can say that, but my reasoning has to do more with her, then her physical attributes. I started crushing on her in Hackers. It was the look in her eyes. You knew she was a kinky girl. That personality captured me. If I catch that glitter of sexual recognition from a woman than I can instantly become attracted.