I love Firefox extensions. The only thing I haven't found is a decent stock ticker extension, ideally to run in my status bar like ForecastFox does.
- Adblock Plus -- of course
- Clipmarks -- new; saves bits of websites. Hoping to stop cluttering up my bookmarks list for something I just want to look at later.
- ForecastFox -- Best. Extension. Ever. Mine even tells me how allergic I'm going to be to the world today and how quickly I'm going to get sunburned. Also, I think it's neat the way it puts an icon in my status bar for severe weather alerts, because the odds I'm watching TV or listening to radio are low, but Firefox is almost always on, so that's a much better emergency weather alert system for me!
- GMail Checker -- meh
- Google Reader Notifier -- I use Google Reader as my RSS reader
- Googlebar Lite -- slightly redundant with the standard search bar already there, but I adore the highlight feature
- ReminderFox -- to-do list & calendar in status bar
- RetailMeNot -- alerts you to coupons when e-shopping
- Zotero -- new; supposed to be spectacular for web research
What extensions do you run?