How do I turn off Gnome Shell Activities Animations?
Solution 1:
In Gnome 3.8, just do this command to disable all animations:
gsettings set org.gnome.desktop.interface enable-animations false
To rollback:
gsettings set org.gnome.desktop.interface enable-animations true
Solution 2:
The accepted answer does not disable animations, but only reduces the animation time to almost zero. This means the animation will still be rendered - you're just not able to recognize them.
Maxwell's answer really disables animations, but on my system (Ubuntu 14.04) the animations are enabled again after a reboot. However, there is a workaround for this problem.
Long story short, you can disable animations with these two commands:
gsettings set org.gnome.settings-daemon.plugins.remote-display active false
gsettings set org.gnome.desktop.interface enable-animations false