lol
Another hilarious thread. Now we have robot Gods? Weren't Transformers created by the Quintasons? Those bionic 3 faced egghead things? How is such a powerful 'dark God' created by a race eggheaded alien cyborgs?
But anyway, Galactus would win based on the simple fact that Unicron is simply a super powerful machine and his power source is easily manipulated (or drained) by the Power Cosmic (a base element of existence). Galactus can manipulate all energy and matter at will. If you know Galactus's bio, you'd know he is the last survivor of the previous existence, and he merged with that existence to be 'born' into the current plane of existence.
Silly plot devices aside, there are only 3 comic book characters more powerful than a fully powered Galactus:
1) God/TOAA
2) Living Tribunal (Second only to the Creator)
3) DC's Spectre* (who is basically the Angel of Death/Wrath of God/God's Assassin [and for some reason he supposedly fears Superman????? DC's writers should be slapped.])
Didn't Bumblebee survive a fight with Unicron? A damn yellow Volkswagon Bug. lol
Besides, most Tranformers other than Galvatron, Megatron, and Majin Zarak don't pack a lot of fire power on the scale Galactus's enemies do, and he still brushes most of them off.
Galactus would win.