Start with the Comic Book Podcast wiki and

ADD:

Nerd Goggles podcast
First Comcs News: The 80's Comic Book podcast

Black Tribbles: Comics and More

Nerdy Show: Atomic Robo Nuts and Nolts

Super Power Cast

Gotham Girls

Daddy Issues: An Invincible podcast

ValiantNewUniverse podcast

Stash My Comics: Ape4Comics

Southern Fried Inkslingers

Tell Me Something I Don't Know
The Comic Book Shoppecast
The Off-Panel Podcast
Omni Comics Podcast
Comicbusters
The Comicbook Podcast
SuperPowerCast
ComiPop visits
Image Addiction's Weekly Round Up
Whispers of the Dark   vid

these have faded:

Amazing Spider-Man Classics

Big Illustration Party Time

Comic Book Nerds in Celibacy

ComicDorksCast

From Yellow to Red: A Daredevil Podcast

The Mighty Shield: A Captain America Podcast

The Newest Rant Podcast

Prime Time Geek

Shatterday Comics

A Taste of Comics

Teenage Wasteland: An Ultimate Spider-Man Podcast

V For Vertigo

Waiting For the Trade

Webcomics Weekly