perhaps I'm just not a RSS purist, but I can't fully get hooked on any stand alone readers. I've tried NNW, Pulp, newsFire, etc, etc, and while they're all great apps, they don't do it for me.
I use the browser so much, that I constantly want its functionality close at hand. Sometimes I want to check something on the blog's site, or search something, etc. I don't like having to open another window to get the browser functionality.
So I've stuck with the Sage extension for FireFox as my primary rss feed reader. That and the new LIVE bookmarks keep me fed.
it's all just personal preference - the browser is my home, so I don't tend to stray too much.