For Those Who Use Firefox, What Are Your Favorite Add-Ons To Use?

There's a ton of them and thus far I only have two, TwitterFox and Read Later, which I both like. Are there any add-ons you guys particularly like that you could recommend to me or others in general? Thanks.

FlashGot and Forecastfox are the only really useful ones I've got bolted on there.

I used GameFOX for when I posted on GameFAQS

I really like Forcastfox. It does what you'd think. It shows you a radar of your area and gives you a 5 day forecast. But I also love TwitterFox. I like FoxTab, which is like the Windows Vista thing, but you can customize it a little. Also Thumbstrips is good. It lets you look at a screen shot of your history and edit your history there.

well, the add-on's I have are: Personas, adblock plus, FoxClocks and Hyperwords. I also use the Camifox theme since it looks cleaner than the standard firefox theme.

The only one I have is download helper.

Adblock Plus, NoScript, Flashblock and Gmail Notifier.

Adblock Plus

noscript, fasterfox, and download helper

Yahoo Mail Notifier, Tabs open relative, new tab button on tab bar, googlepedia, searchbar autosizer, and a cool Xbox theme.

download helper.

Download Helper for sure. And Adblock Plus. I couldn't live without those. I like Personas too.

Adblock Plus - To hide annoying ads, images and flash banners.
 
DownThemAll - To quickly download multiple files off a page.
 
FireGestures - To make browsing faster with mouse gestures and the viewable space larger by hiding the toolbar. 
 
Greasemonkey - With scripts to modify pages like Myspace, Twitter and Youtube, among others.
 
NoScript - To stop unwanted scripts from running on sites without permission.
 
Text/Plain - For easier handling of plain text links.
 
TinEye - To scan an image and find duplicates and variations of it elsewhere. Good for finding higher resolution versions. 
 
Tiny Menu - To combine the menus into less menus. A nice way to clean up the interface.

Chatzilla, Linkification, Gmail, IE Tab, List all images, and right now I'm using the "Dark Revisited" theme. I used to use GameFox back in my GameFAQs days.

BugMeNot, Adblock Plus, Gmail Manager, and Greasemonkey are probably my top ones.

I have Adblock Plus, Adblock Plus: Element Hider, Clean And Close, Colorful Tabs, Fission, Greasemonkey, Stylish, Flagfox, TinyRead, TinyMenu, and Ubiquity. They're all great IMO, and you should try them out. They make web browsing a whole lot simpler and easier.