I use Google Reader eachday to trawl through all the RSS feeds i subscribe to, this is mainly because of the interface and keyboard shortcuts make it very easy to quickly scan items and filter out those of interest. Previously I've been using the sage plugin for firefox, which has worked well, and more recently the feeds bar for IE7-- again the keyboard short cuts on that are great.. for example if you are using IE7 :
Open Feeds CTRL+J
Open Feeds in pinned mode CTRL+SHIFT+J
However, i find Google Reader works best for me, especially the new shared items feature. You can view my shared articles here
http://www.google.com/reader/shared/01316159295444228531
See how Robert Scoble reads 600+ feeds a day