NetNewsWire is finally out of beta, although the beta relesases had been practically trouble free for me.
If you are using an Apple, this seems to have become the defacto RSS application for many people, including me. The differences between 1.8 and 2.0 are tabbed browser windows, standard Apple-like searching, and Bloglines syncing.
NNW 2.0 also handles podcasts and enclosures well. You can set it to autotmatically handle podcast files, either saving them to your hard drive or sending them directly to iTunes for easy syncing with your iPod.
It also includes a copy of MarsEdit, which makes it super easy to post items directly to your blog.