I like it: Google Reader
It's better than: Bloglines
Why the change?
RSS readers are programs or web apps that let you subscribe to rss feeds, so you can keep up with dozens or hundreds of web sites without visiting each one. I described this two years ago and recommended Bloglines as a feed reader. When Google came out with their own feed reader I tried it and wasn't impressed. As they improved it, more and more people were switching, but I still didn't like it as well as Bloglines. The biggest feature I was missing was the ability to manually order my feeds and folders. I wanted my must-reads at the top and the feeds I rarely look at on the bottom. Google Reader still doesn't have this feature, but I finally switched after going through one too many Bloglines outages.

I've been very happy with the switch. Google Reader is so well designed that you don't have as much trouble keeping up with your reading. And I can hide feeds and folders with no new items, so the stuff I need to see sort of naturally floats to the top. The lack of arbitrary ordering hasn't really bothered me at all. A big advantage over Bloglines, is that Reader lets me look at a few items in a feed without marking the whole feed as read. It also has some great keyboard shortcuts, which make navigation much faster than mouse-driven sites.