If you are CSS-addicted, perhaps you should visit CSS Test Suite. It has been upgraded to support CSS 2.1, the latest CSS version before the next CSS 3.0 arrives with lots of new modules. By using this test-suite, you can predict which browser support CSS specification better than the other browser. I'm not sure about this, but i think Mozilla or Firefox will be the best browser that support for CSS 2.1, followed with Opera. IE or Konqueror perhaps will be the last, but once again, i can't quarantee that, since KDE has released it's latest product KDE 3.4 that ships another update for Konqueror.
Try it and perhaps you can give your comments here :)