The primary reason behind the Mozilla Firefox "Cult-Like" following is the availability of so many different add-ons, extensions, plugins (whatever you want to call them) that make the Internet browsing experience so much better for the individual user based on what they use the web for and personal preferences.
Recently, Mozilla Firefox has given users the ability to use other "designer collections" put together for different types of users, as well as the ability to create their own collection.
What are Firefox Collections? "Collections are groups of related add-ons assembled for easy sharing."
This video is a short overview of my favorite Mozilla Firefox add-on's that I've put together as a "Add-ons collection for Firefox" properly named the "ZebOlsen.com Firefox Collection"