utomatic allows you to set up subscriptions for virtually any content linked in RSS feeds: podcasts, videocasts, torrentcasts... Rule of thumb: if it ends in '-cast', you can get it with Automatic.

An RSS reader/media player for podcasts and video podcasts.

"I just recovered the contents of this site after a two-year hiatus." (The advantage of not spring cleaning your RSS subscritions for 2 years or more is that you find out a site you've long forgotton is back online.)

An open source NetNewsWire-like RSS reader. After five minutes playing with it, it basically _is_ NNW, with a few nice improvements (eg. a date field when making Smart groups). If NNW exported subscriptions in groups, I'd switch!

UI to die for, lacking features due to being in alpha, but usable right now. Very nice feed discovery feature already.

RSS/Atom reader for OSX and Windows, interesting continuous search feature