Firefox, but I got no religion for it anymore. I switched back in the day when Firefox (or Mozilla Seamonkey) was the only thing going, and everything else had some major problem. Now you’ve got two really good browsers to choose from. I guess I only switch when something is woefully wrong, though, and so far I haven’t hit that with Firefox. If I ever do, there’s Chrome. Speed/battery life comparisons don’t matter to me beyond a certain threshold of “good enough”. We’re already there as far as I’m concerned–two free, cross-platform products that do everything you need, what’s not to like about that?
I do have fond memories of Lynx though. I even remember Gopher 😉