Recently DL'd this after running firefox for a few months on a couple machines.. I LOVE IT. Opera runs smooth, doesn't seem to bitch about missing plugins that I know I've installed and has MANY more features.
Features such as the ability to clear ALL personal data such as cache, history, and cookies directly off the menu is extremely valuable for those in corprate environments. If you hold right right click and then hit the left click it will take you back a page, doing the opposite sequence (left then right) will go forward, are also nice little features that lend it its functionality. Firefox had compatability issues with serveral websites that used Java based secure logins for me, Opera does not and even opens them in additional tabs appropriately. While on the subject of tabbed browsing, firefox had a few issues with opening seperate browser windows when I clicked links contained from other sources, such as an email in outlook. Opera does not have this issue and also offers many more options as to the behavoir of the tabbed browsing and the addition of a button on the toolbar for creating a new tab with no url in it. Firefox has a similar feature, except when you click it you have to click the address bar to start entering text. Opera already places the cursor there, since its assumed you are ready to begin entering the URL. The password manger within Opera is fantastic as well and surpasses any capability currently within IE6.
Anywho, for anyone happy with firefox or just looking for a solid IE6 alertnative; this browser is it.