I used Google Listen for awhile. I abandoned it for Beyondpod. I picked Beyondpod because I used it for years on Windows Mobile and loved it. Also, it has a few features that I love that Doggcatcher doesn't offer:
1. Categories - I download my favorite news podcast every day, there are some subscriptions that I only need & want to download once in a while, I like to be able to sort these different groups and download them in batches
2. Google Reader Imports - I like the fact that I can import feeds directly from Google Reader instead of having to export the feeds to an OPML file first. I'm always adding and deleting feeds, so this makes it so much easier to keep everything in sync. If you import from an OPML file, it's all or nothing.
3. Paid podcast - I subscribe to the New York times from Audible.com; Beyondpod accepts my username and password so that I can download the episodes right in the app (Doggcatcher may do this; I could not figure it out from the app description; to be fair, this feature is not mention in Beyondpod's app description either).