Because of that latest IE exploit, even the U.S. government is recommending that users switch to another browser for a while. Firefox might be a good candidate—and it so happens that Mozilla updated the browser this morning with a complete user-interface overhaul.
This video from Mozilla shows what's changed:
Dubbed Australis, the new UI has actually been in the works for a couple of years. It started with a series of mockups in May 2012, and we saw it in early, pre-release build the following month. Mozilla has presumably spent the remaining time polishing things up. Whatever it did, the new version of Firefox looks (and feels) pretty slick.
Prospective converts can grab Firefox for Windows, OS X, and Linux right here. The rest will get the UI refresh in the latest auto-update. I'm a Chrome man myself, but I've gotta say, I'm thinking of switching.