Reeder for Mac
As Stephen mentioned, most people predicted that RSS would die off when Google Reader shut down a few years back. The opposite happened. New services and new apps have risen up in its place. He likes Reeder because it can pull in from Feedly, Feed Wrangler, Feedbin, and NewsBlur with relative ease (even with a lot of feeds). Along with being highly functional, it also provides a great reading experience.
Get Reeder on the Mac App Store for $9.99