Line up all the world’s fruits, best to worst, taking into account every rateable aspect imaginable including taste, appearance, price, reliability and seasonality — the banana rests at the exact middle. So I've personally used it as the ideal threshold to rank every fruit I've ever eaten.
Honeydew melon — those bland, watery orbs whose flavor pantomimes a shrug — falls below the banana line. Same for pomelo, one-dimensional pouches of sour. Mango, pure honeyed sunlight, is well above the banana line. Ditto durian, grapes, jackfruit and the clusters of indulgent color that are cherries. But remember, the banana line is a matter of more than mere taste, however.
Apple gets points for convenience and shelf-life; lychee’s brief harvest period fosters nostalgia and longing for nine months of the year; the price of pineapples assures us that fruit should be a human right, not a privilege. These are all above the banana line.
Blackberry deserves appreciation for serving as sources of poetic inspiration (see Plath, Hass, Heany); kiwi has a nice color and its name carries significance for an entire nation; lime is essential for cocktails. These truths do not lift them above the banana line.
There is a lot to consider. Pomegranate requires utensils to retrieve its seeds and is not appropriate for picnics. Peach can be preserved, baked into pies and eaten fresh. Custard apple’s epiphanic flavor is offset by the seeds in its flesh. Think of the dragonfruit: a flaming teardrop with delicate leather tendrils cradling striking red (or white, or yellow) meat. Dragonfruit appears to have come straight from the countertop of gods, which does a great disservice to the way its taste whispers, nearly unintelligibly, across the tongue. Dragonfruit is below the banana line.
The banana line can be applied to more than just fruit, too. Its conceptual use for vegetables is obvious. It’s not a stretch to extend it to dishes, movies and even cities. If one describes a situation as above the banana line, the meaning should be clear. And people? Sure. In fact, if my dream of the banana line as a metric catches on, I will consider my life above the banana line.