FeedDemon
Nick Bradbury, the original creator of HomeSite and TopStyle, has just released a beta version of his new RSS reader/aggregator - FeedDemon (http://www.feeddemon.com).
I must say, it's incredible.
Nick has really put a lot of thought into the UI, and the way that readers want to read their RSS feeds. With both a feature to walk through your articles, you also have the ability to create "Watches" where it harvests your feeds based on certain keywords.
5 starts, 2 thumbs up, whatever... it's a great piece of software that everyone should check out.
Certainly something I'll be shelling out the bucks for.