As I just upgraded my 14.04 installation to 16.04, it booted right up to lightdm.
I had it properly setup to boot in a console before, but somehow it changed the behavior on me.
This is because the computer is now using systemd to boot.
I already had the GRUB variables setup as expected:
But this is not enough if you want to start in the console when running systemd (which is running since 15.04).
systemd has a list of variables you can tweak using the systemctl command. To boot in ...