So, since all the available star systems were already claimed, I spent every single turn developing my economy, and of course my !!SCIENCE!!.
Due to my natural affinity for it, I was around twenty techs ahead of everyone else by turn 100. I was also allied with the local superpower (the other twos being somewhat upset by my borders).
At that time, I began refusing unfair demands en masse. ("Asking me for all of my antimatter for... Open borders? You know very well where you can put this treaty. With the 254 others.")
Now the north-western neighbour was getting increasingly upset by my rebuttals. So I teched military like there was no tomorrow, and popped 6 dreadnoughts with 26 batteries of lvl6 cinetic weapons each, plus lvl6 flak, lvl3 shields and lvl4 armor, and all kinds of goodies.
Needless to say, when the first two rolled out, I skyrocketed from 4th (and last) military power to a firm first. The puny humans crapped their pants and the arrogants north-western dudes declared war instantly. Too bad, a single one of my babies is so impressive their whole offensive force just fled. Then I finished the six of them and sent them to attack their systems.
The most powerful of their fleets have around 800 power. Mine is OVER 9000. Ownage. (I think I once did 12.000 damages... Or would have done if they didnt flee before the disruptive rounds hit
)
Endless space, playing Sophons. Usually pacifists, but don't piss off a guy that has a laser gun when you have a stone knife.