Some great add-ons to make Firefox look like Internet Explorer for people who aren't ready for a 'change' can still unknowingly benefit from Firefox's greatness.
Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
AutoPager automatically loads next pages when you reach the end of a page. It works on a ton of sites,Google,Yahoo..
It works well with most other add-ons adblock plus, WOT and most of the greasemonkey scripts.
You can also try AutoPagerLite.
Useful tools for the nightly tester.
Expands the context menu's 'Search for' item into a list of installed search engines, allowing you to choose the engine you want to use for each search.
Displays an icon in the tooltip or next to the cursor indicating the target of a link.
Use Windows and Internet Explorer Favorites directly from Firefox. No need to import, export or synchronize - the same Favorites appear...
Adds advanced search capabilities to the Firefox address bar. Supercharge the "Awesome Bar" with instant search results that appear as you type!