Non Iowa related losses? Bama to OSU in the natty was up there. Bielama and Wisconsin at the Rose Bowl. I have an irrational hatred of the Ducks, and USC, so every time they lose is good. Nebraska getting owned by Wisconsin 70 - 31 in the Big Ten title game. NW losing the Rose Bowl to a #17 ranked USC (they were a held out of the Bowl Alliance championship by a loss in the second game of the year to Miami OH, and skipped OSU, such a team could not have been for real. I mean it's freaking Northwestern! Until that year Iowa hadn'tlost to them in my lifetime.) in heartbreaking fashion was good schadenfreude.
But my favorite is #4 Michigan to Appalachian State in 2007. That was amazing to watch and I laughed so hard.
Fun little fact about that game. No Michigan team has finished the season higher than 9th since that season. Before that season, Michigan had finished the season ranked in 19/20 years. 12/20 years in the top 10. After that season, Michigan had only finished the season ranked 6 times, and only once in the top ten.. That was the day Michigan football died, under a decade removed from their most recent national title.