JetBrains (of ReSharper and IntelliJ fame) has released v 1.0 of their RSS aggregator, Omea. They are also offering a free license until January 1st 2005, which seems like a pretty good offer given the high quality of their other products I've used. This isn't just an RSS reader though...it also manages NNTP feeds, web bookmarks, and contacts (full details are here and here).
Jayson pointed this out to me so I installed it and am extremely impressed. The GUI (although very slick) looks a little overwhelming at first but almost everything works the way you would expect it to, almost intuitively. “Intuitive” is a relative term, of course, but when I look for a feature, Omea has it and it is right where I expected it so that's good enough for me. It isn't perfect but is closer than any other RSS reader I've tried. If you are still looking for a desktop RSS aggregator and haven't liked any of the many others currently available, Omea may be what you're looking for.
Bonus: you can finally ditch Outlook Express. If only MS would do the same...