Mozilla is a global community project providing open and innovative internet products. Firefox is one of the leading internet browsers – an obvious choice for many users around the world. It provides all the basic features you need to surf the internet and so much more. The newest version, as of this writing (Firefox 3) includes one-click bookmarking & smart bookmark folders, instant web site ID (which helps to avoid online scams and unsafe transactions), smart location bar (if you type an approximate web address, it will find the correct web site for you) and improved parental controls.
Aside from all the features included in the browser, Firefox is famous for the amount of add-ons (which you can install directly from the browser or download here) that allow you to personalize your web browsing experience.
You can change the theme, add image viewing tools, install download managers, social bookmarking tool bars, and do many many more things. I think it is save to say that whatever you are used to doing on the web, Firefox can help you do it easier and faster.
I am definitely a fan.