Man, it’s hard to pick. The Greeks had wonderful stories. The labors of Hercules are pretty neat: https://en.wikipedia.org/wiki/Labours_of_Hercules

My favorite, though, is the story of Narcissus, in part because it’s my favorite Salvador Dali painting.

Also, sidebar, but there’s a Choose-Your-Own-Adventure book where you the reader are thrust in the world of greek myths and it’s awesome. (It’s called The Throne of Zeus.)