B10 - TAMU/tu would be the red-headed step children. We would bring a ton of $$$ to the table (TV revenue from TX) but we would be the outsiders with no tradition or rivalries associated with the conference.
SEC - The amazing matchups are endless and TAMU/tu would fit in athletically. However, I see this conference as a bad idea. #1 they are academically inferior (speaking solely on rankings) #2 inviting the likes of L$U, Bama, Florida, etc... more exposure in the state of TX would be recruiting suicide. Plus for TAMU football, a team struggling to get back to greatness, the SEC would mean an immediate step backwards due to the increased levels of competition and lower academic standards.
PAC10 - There are challenges due to time zones and travel distances but I actually see this conference having the best potential. They are solid academically and good enough athletically to make a strong conference, yet not so good that TAMU/tu couldn't both come in a do quite well. The added advantage is that the PAC10, like many teams in the B12, are desperate to get in on the kind of TV $$$ that the B10 & SEC have gotten and are willing to do something drastic to make it work. Combining part of the B12 along with most (if not all) of the current PAC10 could build the first super conference that would work from a travel standpoint and could garner the TV ratings to justify a big deal.