My favorite Gnome Shell Extensions
Here is my favorite Gnome Shell extensions :
It's a very usefull extension for laptop that allow to control your screen brightness
Place Status Indicator
Simply add an icon for quick folders access
Status icon fixer
This extension fix Dropbox icon notifications on status bar
Just a fancy extension to switch between apps with coverflow style
Dash to dock
"Transform the dash into an intellihide dock."
"Remove the accessibility button from the top panel."
Media player indicator
It allows to control your media player on the status bar via the volume icon
This extensions allow to tweak your gnome shell, but they also show us the importants deficiencies of Gnome shell...
You should look at Gnome shell extension page