Mac: Cream is a feature-rich feed reader for Mac with a beautiful user interface. But what makes it really special is that it knows which stories are most worth your time reading and floats them to the top. As they say, "the cream rises".
Cream offers one-click import from Google Reader, and its method for determining which articles and feeds are "creamier" than others is impressive: the app watches as you scan, read, ignore stories, even within a particular feed. That means that Cream not only can float the feeds you like to the top, but the specific types of stories from those feeds to the top -- so if you like Android posts over iOS posts in your Lifehacker feed, for example, Cream learns this and shows you what you want to read first.
At any time, you can switch between a list of the "creamiest" stories, all feeds organised alphabetically, or all feeds organised by date. Like any good feed reader, you can see everything, just unread feeds and unseen feeds that have come in since the last update. Click any story to open it in a pop-up panel on the right or open it in your default browser. If you see a long article and want to save it to Pocket, Instapaper or Readability, Cream supports all of these things.
When testing Cream, the only downside I noted is that Cream doesn't actually sync with Google Reader, so as you read stories they're not marked as read. I asked Cream's developer about this, and he noted that Cream was designed to be a supplementary tool to your main news reader so you can quickly see the newest and best stories you don't want to miss -- with the assumption that you'll use another app to clear them out later. If you use Cream exclusively, you may not notice anyway.
Cream ($5.49) [iTunes App Store]