Why I still use IE on Windows
IE, despite a host of security flaws and other generally annoying misfeatures, at least doesn't regularly get hopelessly confused about whether a web page exists. Mozilla and its ilk have this annoying habit, at least on a network that's connected through a Microsoft proxy server, of occasionally deciding that a web page just doesn't exist, even if you're using the back button to go back to a page you just exited.
It's really annoying when you're trying to validate a webpage on a nonmicrosoft browser. It's even more annoying when you get hit by a flurry of popup, popunder, popthrough, pop-containing-flash (etc etc etc) pages in IE, because Mozilla and its ilk are very good at refusing to allow those stupid popups.
GRRR! I say again: GRRRR!