What is the greatest love story of all time?

There Will Be Blood, for someone in love with themself.
Let the Right One In(Movie version), for love between two people.
I intentionally removed from consideration Romeo and Juliet because it would be unfair otherwise. I think every good story is ultimately a love story, whether inter or intrapersonal, or whether the love object becomes a thing, ideal, or what have you.
Also, the story of Adam and Eve in Paradise Lost is an amazing love story. At one point in the poem, after they realize what they've done they consider suicide, and you just can't help but imagine all that would have been lost-everyone and everything-had they done so. Adam considers going off alone, and again, you imagine all that would have been lost had they not loved each other enough to stay together. I'm not a religious person but that doesn't matter in the context of the poem. It feels very real. It also has a Romeo and Juliet quality to it, when Adam realizes what she's done and he could forego eating the forbidden fruit, but decides to eat it anyway so she won't be alone before God and judgement.