OSU: Buckeye Talk, Eleven Dubcast, Tim May, Buckeye Weekly (Stay away from Sloopcast. Those two are not built for voice media. They sound like some ham radio amateurs. They butcher players' and recruits' names regularly; they're unbearable. They're OK on Twitter, but on a podcast, stay away...)
Other than Buckeyes:
Mike Valenti Show (if you wanna hear an MSU alum roast Michigan, MSU and Detroit Lions). Now on iTunes, his pods are broken into 8-15 min segments from his radio show. Definitely a good listen when any of those teams is losing.
Spartan Beat (with Rico Beard): A little long to listen about a team other than yours.
The Wolverine.com Podcast: Only when Doug Skene is on with Chris Balas. Balas sucks, but Skene is an intelligent voice worthy of a listen or two.
Non-sports: The Re-Watchables: Kind of nerdy and analytic, but entertaining when you come across an episode where they rewatch a movie or TV show that you liked.
Drink Champs: Skip it you're not a fan of hip hop. Otherwise, N.O.R.E. makes for an entertaining and most times hilarious host.