We need bush type plants that continuously grow back, and bear consistent amounts of fruit.
Examples being: The Raspberry Bush, or the Blueberry Bush. These two fruit bushes prosper in a temperate climate, and blossom/bear fruit 1 to 3 times a year (usually from the spring to the fall (but nowadays those multi-blossomers are genetically modified plants)). Once they bear fruit, they are pruned to nubs and then left until the next year, to hopefully bear fruit yet again.
Quality would come with age. As with any annually growing plant species, the first, or "baby" years, bear far less fruit than an aged plant. Not only this, but the fruit can often become sweeter or larger through years.
A few examples of these wonderful plants (many of them I have growing in my backyard) are:
Peas
Wheat
Lettuce Heads
Blueberries
Raspberries
Bell Pepper Plants (red, orange, yellow, green)
Watermelon