[Rott3n]

tabx. adds a "x" to close tabs.
http://extensionroom.mozdev.org/more-info/tabx

add blocker. custom block banners and adds
http://adblock.mozdev.org/dev.html
get list here http://www.geocities.com/pierceive/adblock/

gmail notifier. this one ownes
http://nexgenmedia.net/extensions/

download manager tweak
http://dmextension.mozdev.org/

and most of the ones Nyck uses