I've got a few favorites myself.
All-in-One Sidebar definitely tops the list. Even if you've never used a sidebar before, I'd strongly urge you to try it.
https://addons.mozilla.org/en-US/firefox/addon/1027
BBCodeXtra is really helpful for forums, it adds BBCode functions to the right-click.
For Example:
Test
Test
Test
hello there wrote:Test
- Test
- Test
- Test
- Test
Test
That was done in about 20 seconds using BBCodeXtra
https://addons.mozilla.org/en-US/firefox/addon/491
Foxytunes is really quite cool. It embeds a music player inside the Firefox bottom bar, and plays music from any music player you have.
The only downside is that you need to have that music player open in the first place.
Another cool feature is that, on forums, there's a small icon where you can embed a Signatune, basically a music track as a signature.
(remember, Gametoast doesn't allow signatures)
https://addons.mozilla.org/en-US/firefox/addon/219
Greasemonkey
This is a really cool addon that was developed by a Google employee that lets you change the way many popular websites look using bits of Javascript.
https://addons.mozilla.org/en-US/firefox/addon/748
The Firefox Addons Main Site - https://addons.mozilla.org/en-US/firefox/
ONE thing though.
Please, Please do not turn this into a Firefox vs Internet Explorer debate.
If you want to do that, make a thread yourself and don't hijack mine.
