I'm a big fan of RSS feeds -- this isn't news. Google Reader, however, just might be news to you, and if it is, you owe yourself a look. It's reminiscent in design to GMail and other excellent Google web apps (expected). It's not perfect (details in a bit), but it's got a couple really nice redeeming features. I think I'm hooked.
The first time I saw Google Reader, I wasn't all that knocked out. First of all, it's not quite as nice to use as a dedicated windows-based RSS reader. The bar has always been set for me by apps like RSS Bandit, which work well because they're purpose-driven, and Windows-based. This is the same reason Outlook is better than traditional web-based mail readers.
As you probably know, web-based email readers are getting better and better, and I'd say they're starting to give Outlook a run for its money (think Yahoo, GMail, and others). Similarly, the Google Reader interface is pretty nice when it works.
Yes, I've had some problems with it working. Fortunately, the problems seem to be platform-related. Reader doesn't seem to paint quite right in IE7, and in Opera, my mouse's scroll wheel moves down no matter which way I scroll the wheel. Not the end of the world, but if you're going to use an application a lot, these types of issues will drive you slightly batty. Good news, though, for Firefox users. Reader seems to work perfectly on this open browser.
Enough on the warts, though. Where Google Reader really shines is when you start using it from multiple computers. Unlike a Windows-based reader, since Google Reader is server-based, it's going to keep track of what you've read on the server. No more re-reading news from one PC to the next. To be fair, some Windows readers like RSS Bandit support mechanisms to synch read lists to a server, but I never had any luck getting that to work. Google Reader works without you having to think about it.
But the real killer feature is sharing. When you're reading news, you have a one-click sharing button that instantly adds whatever article you're reading to a "share" list that's maintained just for you. Here's mine. Now you can watch this meta-feed (it supports RSS, too!) and see what articles I'm reading that I think are worthwhile for others to read, too.