Regular ones:
Bookmark Sync and Sort - Stores all bookmarks on an FTP server so you can synchronize the bookmarks on all your computers, connected from anywhere
Download Statusbar - Way better than normal downloads window
Fast Video Download - Download videos from YouTube, Google Video and almost any other type of embedded video file
OpenBook - Little hack to change the "Add bookmark" window
StumbleUpon - Visit random sites when bored
Web development:
IE Tab - Test how sites look in IE
Quick Locale Switcher - Switch preferred language very fast, to test multi-language sites
Remove Cookie(s) for Site - Quickly removes the cookies for the site you're viewing
Tamper Data - Mess with HTTP headers
Web Developer - Musthave for every web developer IMO
Other stuff:
US + NL dictionaries
Default theme
EDIT: FineWolf, how (with what) did you generate that?