50 Firefox Add-on you should not miss to use

Though there are thousands of thousands of Firefox add-ons.  Everyone has their own personal favorites.  But I am sure some of them are everyone’s favorite.
I am trying to compile a list of best of the best Firefox add-ons and extensions which are useful for specific purpose so that I can quickly install them every time I install Firefox on any new machine.
I will request all the visitors and readers to help me compile this list by suggesting their own favorites and what they find good about it.  I will keep updating this list based on your feedback and after I try it.
Below is the list of 50 of my favorite Firefox Add-ons.  I have categorized the list as per my convenience and based on purpose.  Check it out on Knowliz…