Passive agressive to the max.
I'll play a strong cultural, science or general builder game and when I find myself with a commanding lead I just can't keep from obliterating all in my path.
In my last game, moments from heading for the stars, I couldn't resist nuking the Zulu. I saw their troops coming from a mile away and after they attacked from within my territory I just couldn't let it pass. Within two turns I was at war with all but one AI. I, Smoked Jag, killed the sad little Babs w/ modern armor and nuked the Germans, Russians, Iroquois, and, of course, the Zulu back into the stone age. Seeing my opponents major cities in the middle of an orange puddle of goo just makes me giggle.
This is pretty much how all my games go. Benevolent ruler turned raving madman.
I'm going to stop writing now because I'm scaring myself. Time to medicate and call the therapist.
Absolute power corrupts absolutely.