In my opinion Firefox is the way to go;
-Tabbed browsing
-More secure, doesn;t need to be patched as often
-Open source means it has to be good
-Much more personable
-Extensions
-Faster
-No ActiveX controls = more safe browsing
-Cookie manager, including the option to ask every time
-Allows everything option-wise to be set from the ground-up via about:config
-Developer-friendly
Of course I've skipped many more smaller details, but you get the bigger picture.