Found an interesting bug/exploit/(feature?) in The Eugenics Wars, as the Aegis. This may be an intended feature, but no one's mentioned it so far, so:
The transport sequence unit is an invisible transport. It can move into enemy territory and over enemy units.
However, if I load a visible unit into the invisible transport, and, say, move it into an enemy city, the game tries to put a (loaded) visible unit and visible enemy units into the same plot at the same time, fails, and expells all the enemy units to a neighboring plot.
I then move my 15-speed unit out of the city, unload the unit, and take the city.
If you have enough units and Transport Sequences, you can do this to every city of a civ in one turn, defeat your enemy, and wipe out all their expelled forces, because they no longer control any cities.
Used this to (in one game) wipe out all three Eugenics civs in a couple of turns, (in another) to destroy a major civ in a turn.