[GUTB]

Build a cargo ship with a stealth armor and some Drone Launchers. Fill it up with Drones loaded with anti-planet warheads.

Cloak, and proceed to any habited system of your choice. Launch Drones against system, and COMPLETELY WIPE IT OUT IN ONE TURN.

Go back home, replenish Drones as nescisary and repeat until EVERYTHING IS DEAD.