I think focusing purely on popularity contests misses a lot. Sure, the big ones like 'Vamana the dwarf king' or 'Kurma the turtle' get all the play in kids' books and temple art, and the 'Ramayana' with Rama as the perfect king-avatar is everywhere. But the quieter stories in the Puranas hit different. There's one where he's 'Mohini', this mesmerizing enchantress, to distribute the nectar of immortality after the ocean-churning. That story's got layers – illusion, gender, cosmic trickster stuff. It's less about a grand battle and more about a necessary, beautiful deception. I've always found the 'Bali and Vamana' story uncomfortable, honestly. It's the go-to for explaining devotion, but the dwarf asks for three paces of land and then grows to cosmic size to claim everything? Feels like a legalistic trick on a demon king who was being generous. Makes you think about the stories we tell about power and virtue.
Then there's 'Krishna's childhood' – the butter thief, lifting Govardhan hill. That's the heart-stealer, the one that makes him feel close and personal rather than a distant cosmic principle. In the south, you hear more about Venkateswara and his tales of debt and devotion. The most popular depends entirely on your region, your family, what your grandmother told you. For raw cultural penetration, Rama and Krishna are obviously tops. But I'd argue the most interesting ones are the less straightforward victories.