I have been using firefox in vimperator mode for some time. It is an extremely fun way to browse the web for an vi addict.
Once a vi user, get addict to it I’m sure he will never go back to usual firefox mode using mouse.
I can navigate pages and links, add and search bookmarks and more importanty search the vi way, so much easily without moving my hands off the keyboard.
Of course good old Lynx is still usable in these modern days of the web. It is immensely valuble on certain low bandwidth environments.