This is by far, hands down, the best browser I have ever used.  Its stable, mostly secure, and completely customizable.  Mozilla has an array of themes, and extensions for Firefox.  You can add things like bookmark synchronization, download acceleration, media player control via remote, etc..

You can find the newest most stable version of Mozilla Firefox Here.

Recently, Google has pulled interest from Mozilla Firefox, and has entered the browser market on its own with their release of Google Chrome.  Google Chrome appears much faster for browsing, as well as initial load time.   Built with powerful flash and javascript loading techniques Google Chrome has made a modest presence with its application geared web capabilities.  The release is still new and does tend to hang occasionally for most users. 

While it wouldn’t hurt to try it out, Google Chrome is not our choice for users.  Mozilla Firefox still dominates this market.