Jeff Schilling has been blogging about the state of RSS readers on the PC for a while now over on manicwave:

http://www.manicwave.com/blog/archives/000055.html

He has links to a number of options for those stuck with using a PC and is working on his own news aggregator:

http://www.manicwave.com/blog/archives/000062.html#000062

Jeff has a Mac and knows how much better things for the switched:

http://www.manicwave.com/blog/archives/000044.html#000044

Worth a look.