Starting with the Babylon 5 podcasts known to me now, here is the list :

The Babylon Podcast  :
– 280 episodes
– warning : Massive spoilers in their episode discussion
– Very comprehensive with episode discussions, interviews, discussing books and comics

The Babble On Project  :
– currently running
– essentially spoiler free sections and spoiler sections
– episode discussion, a few interviews.
– sometimes poor audio quality with shouting into the microphones.

Downbelow : A Babylon 5 Introcast  :
– started 2014, currently at episode 30, at the end of season 1
– intended spoiler free, they have succeeded in doing that
– each B5 episode has a discussion episode, some episode commentaries

Braving Babylon 5  :
– started 2014, currently at episode 9
– generally spoiler free, first time viewer of B5
– single host talking about one episode per podcast episode

The Babylon Project Podcast  :
– started 2014, currently at episode 4
– generally spoiler free section followed by a spoiler section
– single episode discussion

The Audio Guide to Babylon 5  :
– started 2014, currently at episode 5
– starting every episode with a generally spoiler free section then a spoiler section present from the beginning
– Single episode discussion

White Star 5  :
– started 2014, currently at episode 4
– spoilers inevitable due to the nature of the discussions
– Discussions of themes, characters etc – no episode discussions

Jumpgate : The Babylon 5 ReWatch Podcast
– Started late 2013 or early 2014, currently at episode 14
– spoilers inevitable due to the re-watch quality
– single episode discussions

SQPN : Secrets of Babylon 5  :
– ran in 2011 for 17 episodes, possibly pod-faded
– generally spoiler free, first time viewer
– two hosts discussing 2 episodes per podcast episode

Wow ! 9 B5 podcasts that I know about, and 6 of them started less than a year ago.
This really looks like a renaissance of the interest for Babylon 5.
That was the quick overview, some more details for some of the podcasts will follow.