Here's my Favorite list of Firefox Add-Ons!

[eSkRo]

CustomizeGoogle:
Enhances Google search results by adding extra information
(like links to Yahoo, Ask.com, MSN etc)
Also removes unwanted information like ads and spam from search results too!
Have a look -> http://www.customizegoogle.com/movies/intro-flash.html


Download Statusbar:
View and manage downloads from a tidy statusbar
without the download window getting in the way of your web browsing!
Have a look -> http://www.firefoxthai.com/blog/wp-content/uploads/2006/12/08_11.png


FasterFox:
Wanna browse faster?
FasterFox increases Firefox speed Performance!
Also adds a popup blocker for popups initiated by Flash plug-ins!
Have a look -> http://fasterfox.mozdev.org/


Foxmarks Bookmark Synchronizer:
Access your bookmarks from any computer at anytime
and never loose them again!
Have a look -> http://www.foxmarks.com/


GooglePreview:
Inserts preview images of websites into Google search results pages!
Have a look -> http://flet.ch/things/greasemonkey/images/google_thumbnails.png


IE Tab:
Ever ran on a website that supports or is optimized only for Internet Explorer?
With one click of a button
this extension let's you run Internet Explorer within Firefox!
From now on
Believe it or not
you can run your Windows Update from Firefox!
Have a look -> http://ietab.mozdev.org/main.png


Paste Email (original):
Tired of entering your email address everytime into text fields?
Then Paste email is for you!
It does what it says!
It can paste your email address or any other text into text fields!
Have a look -> http://customsoftwareconsult.com/extensions/pasteemail/PasteEmail.html


Tempomail:
On demand
it creates a temporary email adresse
valid for a couple of hours
that redirects mails to your real address
thus preventing you from mailbox spam!
Have a look -> https://addons.mozilla.org/en-US/firefox/addon/3883


Unofficial Google Translate Firefox Extension:
It's simply a top noch translator no doubt!
Have a look ->

Unplug:
It let's you save video or audio that's embedded on a webpage!
Yes!
It's a media download tool!
The best of the best right here!
Have a look -> https://addons.mozilla.org/en-US/firefox/addon/2254

[juelz aka wolfi]

dont forget key scrambler and WOT which helps identify harmful websites

[Gaijin]

everytime i get ready to download it my firefox says it doesnt recognize it an that it is harmful to my computer

[eSkRo]

everytime i get ready to download it my firefox says it doesnt recognize it an that it is harmful to my computer

wich extension?