Suggested by Sauroposeidon
The year is UC 0079, in the midst of the One Year War a new faction appears suddenly and with out warning. The Cylons (Battlestar Galactica) appear just after a startling Zeon Victory crushing the Earth Federation at Solomon Island, completely changing the course of the war and leading to near instantaneous Zeonic victory over the entire Earth Sphere. Can Zeon handle the newly arrived force, or will the Cylons take over?
In this scenario, Amuro never got in to the Gundam. Zeon has all of their aces still alive. Char has not yet managed to assassinate any of the Zabi family. With the Big Zam, Zeon completely dominated the Earth Federation and they retained many of their experienced pilots. The only significant losses Zeon have suffered were during the Battle of Odessa. The Cylons have everything as depicted in the newer Battlestar Galactica series. They may use any shown tactics to try and win. Loss can result in one faction being completely life wiped, or simply forced in to indefinite retreat due to loss of resources (such as force Zeon to leave the Earth Sphere as depicted originally in Gundam). The goal is to control Earth, the moon, and the colonies (or destroy them if the faction so chooses.)