Well I reinstalled Firefox so decided to list the extensions that I use and cannot live without. The versions of the extensions are the latest at time of writing.

Make things Faster
Fasterfox 1.0.3 (this should be standard..)
Flashblock 1.5.1 (flash wont play unless you click it)

Make things a little more like the Opera web browser
Mouse Gestures 1.0.4 (Zomg!! this should be standard..)
Crash Recovery 0.6.3 (this should be standard..)
Extended Statusbar 1.2.4 (more stats)
autoHideStatusbar 0.3.6 (this should be standard..)

Make things a little more like the Safari web browser
Fission 0.8.2 (combines progress bar and addressbar like safari)
Stop-or-Reload Button 0.2 (combines 2 buttons into 1 like safari)

Incredibly useful
undoclosetab 20051204 (this should be standard..)
IE View 1.2.7 (view current page in internet explorer - handy sometimes)
FlashGot 0.5.9.993 (integrate with download manager)
Net Usage Item 0.8.4 (usage meter for australian ISPs)
ListZilla 0.7 (creates lists of installed extensions)

My theme of choice clean, clear and simple
Crystal Dream 1.0.2