Right now Firefox is a memory hog, but a ne roll out is expected soon. I still like it better. IE7 is the worst of al of them. IE7 always seem to need to shut down with Vista even with SP1. Safari recently had an upgrade. With the upgrade it is advertised to be faster than Firefox. When the Fireox upgrade is released, it will be a lot faster than it is now
I haven't used Safari but between Firefox and IE, I'd definitely choose Firefox. It is more customizable, slightly more secure and looks better in my opinion. Unfortunately, some web pages ONLY work on IE so you either have to use IE once in awhile or use the IE tab plugin for Firefox.
