Anything plain, out of the Box is unacceptable these days. Add-on, widgets, apps, skins is must. Most IT folks are well aware of Firefox addon and have made Web developer Tool & Firebug as default part of browser. Which other add-ons you use on regular basis? Same functionality could be possible via browser options but addon make it single click and easy to use.
In my day to day task, Ones I have become dependent on are – ShowIP, Fiddler, Remove Cookies for Site, FireShot, YSlow
Good one Dimple ben
FireFox Sync –Sync Your Book Marks, history, tab and passwords wherever you go.
ABP Ad Blocker – When I see movie online or Cricket match on cricvid.com it’s block most of the ad
and yes httpfox
Cookie Watcher – A tool to watch cookies in statusbar
Firebug
1. Echofon for Twitter
2. All in one Gestures
Firebug – Awesome tool for debugging
AD blocker – works amazing
Poster – to test WebServices
Extended Status bar – tells you details about the webpage e.g. how long did it take to load the page, how many images are on the page…