Well, when we first see someone, we judge them completely by their looks. If they are good looking, do they dress nice, do they look like they take care of themselves, etc. So in that respect, looks do matter. That being said, there are plenty of very hot people here at college who are lots of fun to look at, but I would not want to get to know them or be friends with them because they have shitty personalities. Then there are some people who I'm friends with who got shafted in the looks department, but they have a great personality so I want to be around them.
In relationships, I think there needs to be a good degree of sexual attraction to the other person. But obviously a relationship can not survive on sex alone, so the person definitely has to have a good personality. I would much rather be with someone who has a personality over looks instead of the other way around. So I think looks do matter to some degree, but it definitely is not as much as a make or break factor as personality is for me.