The Big 12 has been completely top heavy the last five years. I think 2008 was a decent season with TTech, Okie State, and Mizzou showing life as well as 2007 with Kansas having only one loss. But really it's just been OU, UT, and third team du jour be it Nebraska, Colorado, Kansas State, Texas A&M or Missouri.
I like most of the Big 10 teams especially Northwestern. They've played some really sweet games lately.