I subscribe to Buzz Out Loud and The 404 from CNet, which are both pretty cool. Mostly technology related.. And sometimes Mahalo Daily, but I kinda get tired of it after like 2 minutes. Also, Diggnation (video, but they put out MP3s as well), because it's funny and interesting, even though I'm not much of a Digg user. I'm told NPR has some interesting ones, so I'm trying to get into those, but I haven't really found any I'd listen to regularly yet (they seem to be very..US-related, obviously and while a little bit is okay, a lot is just uninteresting for me (non-American)).
I've just started looking up other podcasts than BOL and Diggnation, so I don't have a lot of suggestions (I've tried many, but not been very pleased), but I'd definitely say BOL, The 404 and Diggnation are my favourites, so far.