Most Browsers (Greasemonkey): If your Facebook News Feed is still clogged with annoying applications and unimportant updates, simple user script F. B. Purity can seriously narrow it down to just the important stuff.
The script doesn't loudly announce its presence; it just sits in the corner of your News Feed letting you know how much it has blocked. Not only will it block annoying applications like Farmville, Horoscopes and other nonsense, but it will also hide unimportant posts, like "Daniel is now friends with three people you don't know" or "Bob likes these three pages you've never heard of". Essentially, it removes everything except status updates, photos and events. If you find your Facebook is seriously cluttered, this Greasemonkey script will cut through the rubbish so you only see the stuff you care about.
F. B. Purity is a user script that works with Firefox with Greasemonkey, Chrome, Opera and Safari with SIMBL and Greasekit.