You may or may not know that I am a big fan of Opera for Windows. I find it personally to be the best browser on the system. I am free tech support to my parents, so after some nasty spyware problems I shifted them over to it. I work day to day for a large firm doing web and graphic design and Internet Explorer is always a pain. I would say however that IE7 combined with Maxthon 2 is a magic combination and really the only way you should use IE at all. I don’t like Firefox much, but it is so much better than IE6 I am compelled to recommend it if Opera or IE7 doesn’t tickle your fancy.
I recently used a Mac for testing purposes and found the multi platform browsers to be seriously wanting. After a bit of testing I decided that I liked Shiira, it is the nearest thing to Opera or Maxthon I could find that ran like a real Mac app. Safari is too light for me and few people will pay for Omniweb. Shiira uses the same webkit engine as Safari, but with a vastly better interface.
IE6 or below is not supported by this website, MS promised PNG Alpha support for years and only IE7 now supports it so if you see my banner with a gray background you have a duff browser.