There are a lot of great games that can't be quantified easily. I challenge you to make a brief synopsis for Xenogears.
If only because I can:
Deus falls to the planet, injured beyond quick repair, and creates life to eventually serve as components for his rebirth. Meanwhile, a small surviving child runs through several incarnations, guided and opposed by Elly and Miang, with the ultimate destiny of putting an end to Deus and freeing the Wave Existance. And we all go home a little wiser.