I've become addicted to using Snackr for my RSS feeds. I like how it does a ticker tape scroll of my "unread RSS feeds."
Clicking on any "headline" results in an RSS summary popup. If I want more details than this summary, I click on the provided link and am taken to the RSS feed page. I personally like this kind of a feed much better than Google Reader.
I like Teaching Science and Math - because of the obvious ties to my students.
I'm interested in trying to find more great RSS feeds to follow. There are now three included in this discussion. How big a list can we create?