My money's on Gary Pinkel, with Bill Callahan running a close second. Not many coaches continually do less with more than Pinkel has demonstrated over his tenure at Mizzou, and given a few more solid recruiting classes I might put Callahan in the same echelon.
Snyder or Mangino are more likely to drop dead than be fired, and ISU is so naturally inclined to suck that the recent semblance of success should have their helmet-wearing, short-bus riding fanbase geeked and amped aout McCarney's job for another decade.