dun, Dun, DuN...DUN!!!

And the winner is.....................
Darth Vader

Oh dear God, I don't want to imagine how much of a one-sided battle that would be for Thrawn...  

This is an interesting and funny thread.

Okay, you have to look at the strengths and weaknesses of each side (and their commander).

Lord Kona is an exetremely smart leader and tactictian, and the Drengin Empire has a very high level of technology and ships. They also have the production to easily replace destroyed ships. So, even though they are smaller the Galactic Empire, the Galactic Empire would have to go through countless ships to reach Drengi. On the other hand the Drengin Empire is prone to power struggles (see Dark Avatar), which could leave them vulnerable.

Darth Vader is an extremely powerful Sith Lord. He is always practicing his fighting and force techniques, while the Emperor sits in his palace doing nothing except being parinoid. He, along with the Galactic Empire is very intimdating. He has the biggest ships (Super Star Destroyers) and the Death Star. However, the Empire is always being bothered by the Rebel Alliance. An originally ragtag group, the Alliance becomes a powerful and organized group by Return of the Jedi. So, the Galactic Empire would have to fight an internal war as well. The last thing is that Darth Vader can't be everywhere at once. Sure, his Super Star Destroyer fleet could win major battles, but otherwise, the Empire could lose. Another thingis that the commanding officers of the Empire are one word: incompetent. They make tons of mistakes. Usually that makes Vader choke them to death, but whatever. The Empire is also to big to properly defend. Vader would have to send his fleet to constantly running around to defend key installations and planets, leaving other places vulnerable.

Kane and the Brotherhood of Nod would be interesting. Kane is a one determined immortal. By the time Nod colonizes other star systems, the Galactic and Drengin Empires would be dominating most star systems. However, Kane would contact the Scrin, convince them that the war between them and Nod was a big misunderstanding. They would then knock GDI to the ground, and start colonizing planets. A thing about the planets, they would be covered in Tiberium. Any unprotected army would killed immediatly by Tiberium's radiatiion (Nod and Scrin would be immune by this time). This will make it difficult to attack Nod. Nod also doesn't worry about defending a lot of planets, allowing Kane to build each planet up into a powerful fortress. However, if the Galactic and Drengin Empires research a way to completely destroy Tiberium (very difficult), and get past the defenses, Nod would be destroyed quickly since it's territory is so small. Even Kane's very determined army would be worn down.

Now, lets say these factions would all declare war on each other. Who would win? The Drengin Empire, that's who. All it takes to defeat the Galactic Empire is to ally with the Rebels (Either faction could do this). Give the Rebels good ships, and they will sneak attack the Empire to death. Vader could be shot down in his personal shuttle, or an A-Wing could crash through the bridge of Vader's personal Super Star Destroyer, the Executor. With Vader gone, the Empire would crumble. To defeat Nod, Lord Kona would simply oder the construction of Terror Stars. They would destroy all of Nod's Tiberium infested system with these weapons, avoiding direct invasion. Not even Kane could survive a supernova.

The Drengin would stand victorius. That is, until Thrawn or the Torians come around...  

Etrius

Whew! That was a lot of typing!