Firstly, I have to give a shoutout to
Out of the Game
4Guys1up (formerly 1up Yours)
Retronauts (1up's retro-gaming podcast)
Sports Anomaly (1up sports game podcast)
Giant Bombcast
The Geekbox
RebelFM
I also listen to all of the podcasts on the Adam Carolla Entertainment Network:
The Adam Carolla podcast
Carcast
Ace on the House
Sportscast with Spider and the Henchman
The PTI podcast
The BS Report
I Love Movies
Dan Carlin's Hardcore History
Radiolab
This American Life
WTF with Marc Maron