I listen to a number, but here's a few I'd recommend:
The Dollop: It's an American history podcast presented by two comedians. They talk about some of the dumber parts of the nation's history, with some of the truely horrible things sprinkled in. Basically things you wouldn't be told in an American history class.
Triforce: Two dads and one nondad talk for an hour, tell stories, and riff off eachother.
My Dad Wrote a Porno: A guy reads his 60ish year old dad's "erotic novel" to two friends. It's very badly written and very funny. Not for children, if that wasn't obvious.