Pac 10 is the best.
I find it interesting in your site because you talk about how the SEC is the premier conference having won the last 4 national championships.
In one of your other sites though you point out the fact over the past decade the Pac 10 has beaten the SEC more then the SEC has beaten the Pac 10. Which makes me wonder how many more national championships would the pac 10 have had if they had had a playoff.
Every year USC would get upset by someone in their own conference which would keep them out of the national championship. It was never by a non-conference team. Especially an SEC team.
(Check out Arkansas-USC twice and Auburn-USC).