Galactus v ALL the Transformers
Galactus got the munchies, after his "bowl", The Silver Surfer led him to Cybertron, out of spite towards the Transformers.
Galactus versus the Autobots + Decepticons on Cybertron.
The Silver Surfer just sitting back and watching, preventing other heralds from intervening.
who wins?
I'm saying Galactus, based on "old school" Transformers.