I stopped listening to Giant Bombcast because it was too boring and I got sick of stuff like listening to them taste food sent to them ad various other random crap.
I listen to WAY too mean podcast (I have several weeks worth of podcast backlog). Here is a list of the ones that update at least once a month or so:
Anderson Cooper 360 (I don't have time to watch the TV show, but the podcast unfortunately is a 20-30 minute version of the 2 hour show)
Ask the Naked Scientists (a UK based podcast where this smart guy answers science questions sent in by e-mail and phone calls)
CAGcast (although they sometimes stray into the same traps GB does when CheapyD does a lot of burping and talking about his illegal weed habit)
Common Sense with Dan Carlin (a commentator who talks about various political issues)
Dan Carlin's Hardcore History (where Carling talks about various issues in history)
Dilbert's Animated Cartoons (short 30 second cartoons done by RingTales Studios)
GameTrailers Wii
GameTrailers DS
GameTrailers Video Interviews
GameTrailers Video Reviews
IGN Comics Smash
Keepin' It Reel (movie podcast by IGN Movies)
IGN Digigods (by IGN DVD)
Tech Fetish Podcast (by IGN Gear)
Channel Surfin' Podcast (by IGN TV)
Game Scoop (although it's getting annoying since they opening admit that they don't like the Wii)
Podcast Beyond (similar to Game Scoop)
Nintendo Voice Chat Podcast
Three Red Lights
Infendo Radio
InfoMania (I would watch the show, but I don't get Current TV on my satellite package)
Larry King Podcast (same problem as AC360, it is a 45 minute show but the podcast is usually 20 minutes max)
Mad Money w/ Jim Cramer (I am too busy to watch the TV version)
Countdown with Keith Olbermann
The Rachel Maddow Show (the previous two I love, but I don't get MSNBC)
NASACast Video
NPR: Pop Culture Podcast (a 15-20 minute recap of pop culture stories on NPR in the past week)
Radio Trivia Podcast
NWR Newscast
President Obama's Weekly Address
Pro Wrestling Report on ESPN Radio
Radio Free Nintendo
Remember When (a movie podcast where they tend to talk about older movies or theme episodes, like dedicating 3 episodes to talk about each Matrix movie or 3 episodes for the Star Wars prequels)
White House Speeches
1UP.Com (they have changed the name many times: 1UP Yours, Listen Up, 4 Guys 1UP, and the current name of In This Thread)
Retronauts (which has now been as good since the whole 1up.com being sold to UGO situation)
There are others I subscribe too but don't update that often.
Shaymin, Idle Thumbs has said they are ending before. They said their last podcast would be in November 2009, then they started again in February 2010. I wouldn't be surprised if that happens again. I stopped subscribing anyways because I already had enough video game podcasts.