Once you get to know them, it's different. If there is a personality clash, no matter how attractive the other is, it is impossible for an intimate relationship to bloom. But if you fit like a puzzle, then looks will be considered as a bonus, not the major factor. I think compared to attributes like honesty and faithfulness, physical attributes can be forgotten. I would much rather be in a relationship where I trust the guy than have an awesome boyfriend where I am worrying about him lying to me.
Looks are great, but personality is more important.
Personality is what determines whether or not a long-term relationship will work. If I dislike the person's personality, then there's no way I'll be able to stay with her for more than a week no matter how attractive she is. We have to be compatible- not necessarily similar, but able to balance the other's weaknesses with strengths and vice versa. The thing about looks, however, is that I don't want to ever have to feel ashamed of my mate. If she's careless about her appearance, then I'm going to feel embarrassed for her, and we'll never really be comfortable together.