Interesting poll results.
You're all wrong, except for the *one* that voted for the Citadel Council. The Borg are allergic to bullets, and Mass Effect is all kinetic weapons. Maybe if they assimilated kinetic barriers? But still, my bet would be on the Citadel powers.
The year is 2183. Eden Prime has just fallen to an unknown assailant. But in this AU, it's not the Reapers led by Sovereign, but a large, mysterious cube-shaped vessel. Who wins this war?