I currently use Waterfox. It's the 64bit variant of Firefox. Works great, no crashes and runs really fast too.
Only think I have about this thread is that people are "dissing" Internet Explorer. Why do it? Out of all the versions of Internet Explorer, IE9 (excluding IE10), has to be the most secure browser. I've done multiple tests on it and it's blocked every link I threw at it. It's phishing filter, is excellent, at times it's better than Chrome and Firefox. Just because it's Internet Explorer there is no need for people to "diss" it. Works really well and even better at times when it comes to security, also it might not be good at the addons and spell check (one thing that is a big let down) but apart from that it's security it excellent.
Just my opinion on what people have said about Internet Explorer.