I just can't choose between the ACC/SEC/BIG 12
The ACC is bringing Miami, Florida State, Virginia Tech, and Georgia Tech. To me, the ACC is strongest at the top. In any given year I don't want to play Miami, Florida State, or Virginia Tech. The bottom part of the conference is EXTREMELY weak however.
The SEC brings a ton of solid teams, but year in and year out they have been horribly inconsistent (save Florida). LSU is up right now, but are they really a perennial contender? Tennessee, Georgia, Auburn, Alabama, even Arkansas... any given year they can make a good run. They lack the strength at the top of the conference.. but top to bottom it's a very solid conference every year.
The Big 12 is solid at the top with Oklahoma and Texas. Nebraska has been great in recent memory. In the middle K-State, Missouri, Oklahoma State, and Colorado are always pretty good. However, Kansas, Tech, Iowa State, and Baylor are generally horrible teams.
So top-to-bottom the SEC is probably the best conference.
At the top the ACC is really good.
In any given year the top 5 big 12 teams are generally better than the top 5 in any conference...