What's your favorite Firefox extension(s)?

[R Gaba]

With Firefox, Internet Explorer, Opera, Netscape, Chrome and Safari all competing for the title of the "Optimal Browser" I still think Firefox has the most to offer. Many people don't know about some of the great Add-Ons available (for free) in Firefox. What Add-Ons do you use?

My favorite extensions include:
* Adblock Plus
* Adblock Filterset.G Updater
* Customize Google
* IE Tab
* Tab Mix Plus
* Forecast Fox

And if you use Gmail, these are really nice to have...
* Better Gmail 2
* Gmail Manager