Best firefox extensions

Firefox is one of the most famous web browsers available today. It is the most extendible browser which is largely due to firefox extensions. Firefox extensions "are small add-ons that add new functionality to Mozilla applications. They can add anything from a toolbar button to a completely new feature. They allow the application to be customized to fit the personal needs of each user if they need additional features, while minimizing the size of the application itself" (from the official Firefox Extensions site). Here are my picks for the Best Firefox Extensions:

1. Scrapbook: "ScrapBook is a Firefox extension, which helps you to save Web pages and manage the collection." Internet Explorer also has this ability but it doesn't provide the power which is provided by this extesion. This extension is the best of all firefox extensions available today.
2. Web Developer: This extension adds a menu and a toolbar with various web developer tools. A must for budding developers like me.
3. Grease Monkey: Greasmonkey allows you to execute user scripts depending on the site you visit. There are thousands of scripts available at userscripts.org. Just have a look.
4. Scribfire (Performancing): If you are a blogger you got to love this one. No need to visit the site to post. Just click the little icon showing in the status bar. Setup the account and start posting from the browser itself.
5. Adblock Plus: Adblock Plus in an extension which, as the name suggests filters advertisements from the pages you visit. The filters are updated regularly and it loads the page much faster.
6. Sage: Sage is a lightweight RSS and Atom feed aggregator extension for Mozilla Firefox. It allows you to read feeds right in your browser.
7. No Script: This extension allows JavaScript, Java and other executable content to run only from trusted domains of your choice, e.g. your home-banking web site, and guards the "trust boundaries" against cross-site scripting attacks (XSS). Such a preemptive approach prevents exploitation of security vulnerabilities (known and even unknown!) with no loss of functionality...
8. Flashgot: Download one link, selected links or all the links of a page together at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers. Supported download tools are dozens, see http://flashgot.net for details. This extension offers also a Build Gallery functionality which helps to collect in a single page serial movies and images scattered on several pages, for easy and fast "download all".
9. Tab Mix Plus: Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager with crash recovery that can save and restore combinations of opened tabs and windows.
10. Minimize To Tray: Minimizes Mozilla windows into the system tray. Also includes a right clickable tray icon menu to further load only the windows you want visible. MinimizeToTray's extension options allow you to configure your desired behavior. The three options are:
1. Always minimize to the tray instead of to the taskbar.
2. Minimize to tray on close.
3. Require a double click to restore from the tray.

There are ofcourse extensions which i have left or forgot to mention. Please leave comments and i would update the list as soon as possible.