My idea is something that includes a range of types of housing, at least 2 different types of food stores, at least 1 24 hour convenience store, a medical floor or two, at least 2-3 restaurants, at least 1 coffee shop, a bank branch, et c.

Some of these might need to be ground floor so that they can leverage the foot traffic in the neighborhood, but it might be possible to build the lowest few floors in a mall style around a 3-4 story central atrium so that the retail locations can be visible to anyone who walks in, sort of similar to the Berlin Hauptbahnhof that has pharmacies, food, retail, grocery, et c: all visible when you walk inside.

You'll know you've got it when a particularly indoorsy type could live inside the single structure for months to a year without leaving the building.