I hear NetNewsWire has an excellent RSS Reader for the Mac, and now Safari has one. I didn’t really get the point of having one until I saw the short movie explaining RSS by Common Craft.
This is the dialog box showing at Safari > Preferences > RSS
The way it works is, when you see an RSS icon on a webpage, click the icon to create the feed link, and save it as a bookmark in the Bookmarks Bar. The aggregate will show up at the bottom of that bar’s category.