04/11/08: I've tried many, but NetNewsWire is my favorite feedreader.
It's a Mac-only (the PC version from the same company is FeedDemon) client, which means that you can read items offline, and it supports firewalled and password-protected feeds. Why I love it:
- it can easily handle volume (no peformance issues with ~200 feeds) - allows you to group and sort feeds however you wish - one-click integration with del.icio.us bookmarking service - easy to open items in your favorite browser or open and save in the reader itself - clean UI, that I can customize by choosing from themes and/or editing CSS for themes
