Set default terminal in Ubuntu 12.04

I've set the default terminal using sudo update-alternatives --config x-terminal-emulator but every time I press Control + Alt + T, it still opens up gnome-terminal.

I would like to change it to terminator if possible :-).

If it helps, I'm on Gnome Classic.

The reason why your keyboard is opening gnome-terminal instead of terminator is because the keyboard shortcut is explicitly mapped to gnome-terminal and not the default terminal.

So, you can try remapping your keyboard shortcut to point to terminator instead of gnome-terminal.

Search for Keyboard in the dash overview and go to Shortcuts tab. Then move to Custom Shortcuts and add a new entry with the command pointing to x-terminal-emulator and reassign the shortcut to Ctrl+Alt+T.

(Reference)