My normal "work" browser is configured with the following:
AdBlock
Checky
Extension Uninstaller
Extension Uninstaller API
Linky
Live HTTP Headers
Lorem|Ipsum Content Generator
Mouse Gestures
Preferences Toolbar
Preferential
Tabbrowser Extensions
Tabbrowser Extensions Tab Session Management Module
Themer
User Agent Switcher
Web Developer Toolbar
The combination of all of them makes for a nice shiny useful tool for daily work.
Here's what the top of my browser looks like on a light day: