Google Chrome is by far the FASTEST browser out there, I've tried just about them all, and "Safari" seemed quite the fastest one, though upon installing Google Chrome, it by far was the best browser I've ever used, and not to mention, IT'S STILL IN BETA! It also has a malware/virus detection service, which will redirect you to a page, stating the site is a potential threat, and you may continue, or be redirected. There are more features to it, though I listed two. Speed, and malware/etc detection.
I still have Firefox downloaded, but I never make use of it, unless I want to view something non-HTML.
I suggest using Google Chrome, it's still in beta, but already kicks FF3 off the charts.
At least give it a go, seeing as it after all is the fastest out there.