I was just wondering what addons people had cause i could use with some good ones.

I have

Downloadhelper - good for grabbing random embedded files
Faviconizetab - good for lots of tabs (or don't want anyone to know what your on, lol)
Media Converter - Very quick for downloading instantly converting you tube videos and other video sites
Adblock Plus - Gets rid of ads
Download status bar - very very good for organisation
splash - adds a splash screen* at the opening of firefox
Undo closed tabs button - title says al

*a splash screen is the loading screen before a application starts up

so what do you have then?