.. and give me an extension
I am a fan of Firefox for quite sometime now. Something I am proud of. Well, OK, that's a bit over the top. But I am very pleased with Firefox. One of the main reasons for using it is the simple way one can extend the functionality with all sorts of extras.
Yes, I have fully pimped my Firefox. It's not completely bling-bling, but it has many features that makes my life a bit easier. At least while browsing the web. See the screenshot below that I Photoshopped together. I have a rather long list of extensions installed which I use on an almost daily basis.
For anyone interested I categorize them below and explain a little bit about each of them.
Web design & development
Does a lot more than just pick up colors. Adds zooming and info about elements in the status bar.
View formatted source
It shows a very nicely formatted tree of all the elements of page. Great tool for finding out where you misplaced that closing div.
View Rendered Source Chart
Well, this is an absolute must have for web developers.
Measure elements on screen.
Puts the page through the validator and shows errors and warnings.
Show the outline of a page in the sidebar and navigate quickly through it.
It has it's idiosyncrasies and maybe a bit slow, but it is a great debugging tool.
Fangs Screen Reader Emulator
Shows a text version of what a screen reader outputs. Great for accessibility testing.
Search Engine Optimalisation
Google Pagerank Status
Shows the Google Page Rank in the status bar.
Basic SEO tools.
Adds more SEO info in a tooltip like window, from Yahoo and MSN as well.
Well, the name says all.
Add n Edit Cookies
Again, very good name.
High lights field that can be filled automatically.
Like IE also has.
Enhancements to Google research pages.
suggest search terms while you type.
Preview the target of a link in a small tooltip window.
CuteMenus - Crystal SVG
Adds nice icons to menus.
Saves your session when closing Firefox, so that all opened tabs come back on restart.
When you use Cruise Control this one beats the icon tray application.
Last but not least
This one is one of the best. It adds the possibility to run user scripts on any page. There are so many user scripts created by so many people that probably at least one will suit you.