Yesterday, Apple released Safari 5.1 which brings several great improvements - notably, WebKit 2 along with its split process model, a reading list feature, new CSS3 features, new privacy features such as viewing the data websites store, HTML5 media caching, MathML and WOFF support, download manager improvements and auto session resume (a feature that IE8 did away with!).
With IE9 also doing away with the search box, Firefox losing its way and Chrome still targeting minimalists, I think Safari will now be my primary browser of choice. Its user interface remains more customizable than IE9, it doesn't abandon Windows XP users (not yet at least), and doesn't try to ape other browsers, losing its originality. I highly recommend Safari over Google Chrome v999, Firefox 4/5/6/7/8 or whatever and IE8/IE9.
As a bonus feature, only Safari manages to correctly save user names and passwords on the new Hotmail sign-in page that Microsoft put in place of the now discontinued Live Sign-in Assistant. All other major browsers (IE, Firefox, Chrome and Opera) do not save and autofill Live ID passwords.
Now the reason why I recommend you try Safari is because IE9 is utterly dumbed down. I like the superior usability of Internet Explorer until IE9 came along and destroyed it completely in a single release.
Edit: All good things come to an end, while the bad things always continue. Apple has discontinued Safari for Windows probably because it was unpopular. :( More scope for the evil Explorer team to spread their evil and dumb down internet browsing to a chromeless-frame without any features.