I'm using Helvetireader right now after I switched from NetNewsWire but people should be aware that the developer is no longer updating it because he moved to using the Fever reader.
I don't consider Fluid by itself enough of an option because you might as well be using Safari and it lacks the redesign of Helvetireader.
Right now there are almost no options except one previously mentioned in this thread, Eventbox ($25.00), and NetNewsWire.
Yep, but it didn't quite work for me the way they did it. There was something wrong for me everytime I tried to edit the Javascript file. I had to download XCode and use the script editor for it to work in my case.
It's a great design but since it's no longer being developed it will be broken once Google changes anything. If someone is willing to pick up where the developer left off that could change.
I really like NetNewsWire, just because it syncs with google reader so I can see my RSS feeds anywhere and don't have to go through and update which ones I have read.