Originally Posted by DrCosmic
Unicron and Galvatron.
Seriously... some obscure guys ain't gonna interest me at all. It can't be anyone who I would think: "Oh, a second rate Megatron?"
Bay and Co. got kinda got lucky NOT having Megatron be the main villain again in TF3. especially considering that they marketed Shockwave as the main villain. Unicron and Galvatron are the best possible choices for the villains. Maybe if they decide to bring other worlds into play, they can have the Junkions. This would be GLORIOUS for Michael Bay considering they speak, essentially, like the Bumblebee does.
But yeah, at this point, Unicron and Galvatron are the most sensible choices. However, bringing in Hot Rod/Rodimus Prime would be a whole other story. It would mean killing Optimus off "permanently" again and that went over SOOOOOO well when they did it in 1986.