I had a dream once that Colorado and Colorado State were in the Big 12 (I live in Denver, and cause drugs). Break up with WVU and bring back Missouri and I'd be alright with that confy. Would obvi never happen, but it'd be chock full of rivalries and kind make sense geographically.
Classic Nortards: CU, CSU, KU, KSU, ISU, MU
South: OSU, OU, TT, UT, TCU, BU