Oh, you almost forgot QuickInbox Generator!
also like to add colorzilla plugin ColorZilla for Firefox - Eyedropper, Color Picker and much more
Advanced Eyedropper, Color Picker, Palette Viewer and other colorful goodies for your Firefox
Ad blocker is my favourite lol... pages load much faster when it is enabled
ScreengrabSenseoScreengrab! is an extension that makes it easy to save a web-page as an image – it’s a screen capture tool for Firefox!Web developerSenSEO analyzes web pages and tells you how good they fulfill on-page Search Engine optimization criteria.HeadingsMapThe Web Developer extension adds a menu and a toolbar to the browser with various web developer tools.The extension generates an index (or map) of any web document structured with headings (in the main document, and in frames and iframes that contains), indicating the level of the headings and its possible errors.
FireFTP, followed by AdBlock Plus. I don't like to boggle down with too many extensions, though.
i have used seo and the nodofollow...
I have none at the moment but use to have SEO For Firefox and DownloadThemAll.
FoxyProxy, Flip3d, Download Helper and Fire Bug
Follow me on Twitter: @hendricius
All these addons which mentioned here are most important addons of firefox for Managing, Development, Promoting, Researching and various other tasks but I wan to add one more addons which is screen grab for quickly capture an entire web page,the visible portion or rectangular selection so you don't need to print a page.