One thing I LOVE about Firefox the most is tons of great extensions. I try to stay on top of things and once a while I dive into Mozilla’s extensions repository to see if there have been some good additions. I test those that look promising, and during those few years since I started using Firefox I collected some that I can not imagine surfing without (alphabetic order).
Adblock Plus – a must-have for everyone. With addition of Filters it’s my first line of defense against ads. It enables you to filter links, adds, flash and ActiveX from websites using blacklists and whitelists (you can use wildcards, for example *banner* will block everything with banner in name). I absolutely couldn’t live without it.
Aging Tabs – very nice little extension that you won’t appreciate until you use it for some time. Basically if you have open several tabs it will change color of every tab with time, or every time you switch active tab (that’s the mode I use). You can set start color to white and end color to dark gray and you will be able to at one glimpse to see that you opened a tab and didn’t look into it for long time. (Which may mean that you didn’t look into it at all, or just simply forgot to close it).
CuteMenu – adds icons to menus, witch greatly improves readability.
Down them all – download manager with ability to pause, resume, download file faster in several parts. It has this nice option down them all, that opens a window with all links in active site, you can then set a mask, and get many files in one go.
Link Alert – when you mouse over a link it adds little icon next to the arrow, indicating, type of link target (is it a site that will open in other window/tab, is it secured/unsecured site, image, video, torrent, and many more). Very nice.