FeedDemon, the popular RSS feed reader for windows is/was one of my favorite application. It has a clean user friendly interface and reading/managing the feeds is a treat with this application. Its also one of the few desktop based readers which can synchronize with an online service -Newsgator. However FeedDemon comes at a price (30$) and I have been searching for a good alternative to FeedDemon from some time now.
I did try to shift to Google Reader many times but somehow I found the UI sluggish and for certain operations (marking feeds read) you have to go through a lot of clicks.
RSS Bandit is another free desktop news aggregator (also a open source project) for Windows built on the .NET Framework. The user interface/menus are very similar to that of FeedDemon and is definitely looking like a good alternative to FeedDemon. The UI response is not as fast as in FeedDemon but it has all the features that you would need from a good desktop based RSS reader.
If you are bored with your current desktop reader or the online reader, give RSS Bandit a try.