I think T3 would win, he seems to be the more combat ready one of the two. G0-T0's strength is organisation and economics. I actually like G0-T0, he made me a lot of money over the game and I liked his story a lot. He is also a big floaty Hal-9000 looking droid, whats not to like?
Statement: Peace is a lie, there is only passion.
Statement: Through passion, I gain strength.
Statement: Through strength, I gain power.
Statement: Through power, I gain victory.
Statement: Through victory, my inhibitors are broken.
Conclusion: The Force shall free me.