I have little list of my firefox addons. here it is,
1). Extended Statusbar
Adds an Opera-like statusbar that shows:
- percentage of the page loaded,
- number of loaded images,
- bytes downloaded,
- average download speed,
- load time.
2).Firebug (as you said.But no need to give its details)
Flagfox is an extension for Mozilla Firefox that shows a flag icon, either in the status bar or in the address bar, indicating the current website's server location. It uses relatively little resources, and works by accessing an IP address database contained within the extension rather than relying on top-level-domain roots like ".com" or ".uk".
This is a great tool for web developers, since you can easily see how your web page displayed in IE with just one click and then switch back to Firefox.
Looks for broken links on page,links not working properly.
Screengrab! is an extension that makes it easy to save a web-page as an image – it’s a screen capture tool for Firefox!
7)Selenium (as you said.But no need to give its details)
To check for sql vulnerabilities
The Web Developer extension adds a menu and a toolbar to the browser with various web developer tools.
Resize your browser to various standard resolution sizes.
Let me know if you have more than it..I will installed it.
11) SeoQuake SEO extension--Its useful to find the helping web masters who deal with search engine optimization(SEO) and internet promotion of web sites. Seoquake allows to obtain and investigate many important SEO parameters of the internet...