Mis extensiones Firefox preferidas:

Fasterfox
http://fasterfox.mozdev.org/index.html

Foxmarks
http://www.foxcloud.com/wiki/Main_Page
https://addons.mozilla.org/firefox/2410/

gTranslate
https://addons.mozilla.org/firefox/918/

Tab Mix Plus
http://tmp.garyr.net/

Adblock Plus
http://nave.escomposlinux.org/productos/extensiones/adblockplus/

File Title
http://www.jasnapaka.com/mozilla/filetitle/

Pearl Crescent Page Saver
http://pearlcrescent.com/products/pagesaver/