Currently using Firefox 3.0.3
I really like Opera as a browser, and I used it as my main browser for a while, but there are a few site incompatibilites so I went back to FF.
I do also use IE quite a bit - say for eg if Im doing something for the site i'll check it in IE first. I also quite like something thats called "IE developer toolbar" which is an add-on but very useful if your site uses CSS.
Same if Im working on some modifications on the forums/ changes to layout, i'll normally be logged in as admin in IE so I dont mess up my cookies.
So.. for general surfing its FF, but for working on the site its IE.
Google chrome is a
no for me.