Firefox is just great for most everyone because there are so many more features, plug-ins, and themes than IE does (and you have to pay for some of IE's). I tried Safari, but the user interface didn't agree with me. I didn't think it looked good, and it seemed slow to me.
... Bt that may have been because I had one IE and one FF up wth it most of the time. xD
Firefox agrees with me very well because I have a nice, subtle, black and blue theme, an AdBlocker, and Speed Dial (it has thumbnails of different websites that you commonly go to) as my home page. And if you forgot the URL of a page, but remember part of it or the subject, it'll know what you want. It's really just incredibly handy.