Firefox is great, the best browser I've used standalone say for maybe opera, the possibilities with extensions has made firefox a necessity for me. The following extensions add so much functionality that they would hopefully be included one day in the browser itself, significant enough to want yet small changes and additions that when added you may wonder how you did without them.

All-In-One Gestures

I admit I don't use this, but to some it's a great feature add on making browsing simpler to those who can grasp this concept unlike myself :) it's worth trying out.


All-In-One Sidebar

This is a fantastic add-on that would simply make life easier in firefox.


Download Manager Tweak

Adds more functionality to the download manager window, also allows you to open it in the sidebar.


Download Status Bar

A feature from Opera so you can see the progress of your download imediately without having to find the download window.


Fasterfox

Well, this just simply tweaks and speeds up Firefox - a must.


Fire FTP

Builds into Firefox a great FTP application/Add-on.


Foxmarks Synchroniser

Synchronise your bookmarks between your computers, a very handy feature if you are taking your laptop away.


Options Menu

Adds a menu item in the tools menu that allows quick access to the preferences and options of your installed extensions and add-ons.


PDF Download

Gives you options on how to view pdfs or download them directly.


Restart Firefox

Adds "Restart Firefox" to the file menu.


Session Manager

Manage your browsing sessions with ease, and get crash recovery to automatically restore your pages on reopening firefox after a crash.


Xippee Firefox Extension

Help with your search results - add or remove words to your search criteria.