Windows/Mac: Most of us are using cloud RSS readers these days, but if you want something that runs on your desktop — and makes your feeds pretty — Sputnik is a new RSS reader that does a good job.
Sputnik isn't overflowing with features, but it's still quite young. It's pretty, has solid keyboard navigation options and a lot of promise. Think of it kind of like a young Reeder, but one that's also available on Windows.
If more traditional readers like FeedDemon are just too ugly for you, Sputnik may be worth a shot.