The Pac 10 has one very good team this year. In year's past, CAL and UCLA have been better and the OR teams have had good years with major upsets -- OR ST has beaten USC 3 of the last 4 years and USC has very very good.
I think since the BCS was put in 1998, the SEC has won 4 of 10; the Big 12 2 of 10.
I believe top to bottom, the SEC and the Big 12 are best conferences this year.