I use
Opera always (when my computer isn't broken). It has tabs for a real MDI (ignore if you don't know what MDI is).
It's extremely fast (the fastest browser on Earth), especially with its
intelligent (not like Fx's) memory usage. Mouse gestures lets you hold a certain mouse button and just move the mouse in a direction/pattern to perform an action. With voice support, Opera will read and listen to you (I don't use the voice much). The mother of customisability, you wouldn't recognise my Opera setup, I have it just how I find it easiest (laziest
![:p](images/smilies/msn_tongue.gif)
) to use. It lets you make custom buttons to do whatever you want.