NetNewsWire is the granddaddy of RSS readers, and v4.0 is now ready for you in beta form. It still doesn’t really sync, but it brings the arrow-based navigation from the previous incarnations of NNW that might make it the fastest news reader on your Mac.
Google Reader is set to be switched off in a few days, but many people seem to be focusing on the loss of the web-based reader app. The real loss will be sync, the Goggle backend which ceaselessly queried the RSS feeds of the internet and cached the results, letting any of your client apps (Mr. Reader, Reeder and so on) sync ultra fast. Compare this to the bad old days of RSS sync where your app would have to query each and every feed for you. Zzz.
So NNW won’t be syncing with Google Reader either, but as I remember from many years of NNW use, it’s still pretty fast. And as it is free until the the launch of the final v4.0 (whereupon it will cost $20), you might as well give it a try.