My favourite Firefox addons

1. CookieSwap
2. Firebug
3. Google Toolbar
4. MeasureIt
5. ReminderFox
6. Thunderbird Biff
7. Toggle Web Developer Toolbar
8. Web Developer

I am not using Adblock Plus, since I wants to see ads to update my knowledge.
And yes download video helper once crashed my firefox so I am using Keepvid