Here are some
Must-Have firefox extensions to boost your browsing experience :)
SessionSaver My Favorite firefox extention, It saves your tabs, so that if you quit your browser, or it crashes, you come back up with the content of your tabs perfectly preserved.
Greasemonkey is an extension for more extensions. It lets you add bits of code and HTML to the web pages you visit in the form of "user scripts."
BugMeNot extension has long been one of the most popular enhancements for Firefox. It allows you to use the web-based, registration-avoidance system of the same name without the hassle of surfing to it and querying its database by hand.
and finally,
AdBlock (the name is pretty descriptive)
