VodCasts is a broadly general directory of video podcasts.
They have a single level hierarchy of topic categories. They don't have other categorization like tags, so one might think the individual categories would have lots of listings. Rather than paginate their listings with just a few per page, they seem to put all items in each category on one long page, and curiously the categories I've looked at aren't enormously long. So I don't know what's going on.
The show listings have a description of the show, and also the episodes. There's a player you can pop up to view the episodes.