[Suicide Junkie]

From the sounds of it, you have a bloodthirsty happiness type of people.

So, declare war and kill some alien scum, and your people will rejoice.

Also, build cheap, unarmed troops and spread them out about 20 on each planet. That'll send all your planet's happiness through the roof.

PS, don't lose battles, cause your people hate that, and will drop towards rioting.