ABC "Conversations" always have a few interesting guests on.

Another ABC one, "Nerdzilla" is two guys from Tasmania talking things like movies, comics, technology. Probably my favourite podcast because of the Australian perspective.

"WTF@TFW" is always good, even if it does take me a few days to get through.

"AstronomyCast" can hold my attention if the topic is interesting to me.

plus a few that have already been mentioned.