There are a lot of different RSS readers. Some work as web services, and some are limited to windows (or Mac, PDA or UNIX). Here are a few I have tried and liked:
NewsGator Online - A free online RSS reader. Includes synchronization with Outlook, viewing TV content with Media Center Edition, and publication of blogs and headlines.
RssReader - A free Windows-based RSS reader. Supports RSS versions 0.9x, 1.0 and 2.0 and Atom 0.1, 0.2 and 0.3.
FeedDemon - A Windows-based RSS reader. Very easy to use and has a very orderly interface. However, this is not freeware!
blogbot - An RSS reader plug-in for Outlook or Internet Explorer. The light-version for Internet Explorer is free.