Jan, is there anything better than a fresh-off-the vine, sun-warmed tomato? I think not. I've been lucky here in NYC to have the Union Square Farmers Market available to me for sampling different kinds of produce. Besides tomatoes, then, I'd be tempted to plant Fushimi peppers, a Japanese variety that is not "hot" but quite nice simply sauteed in oil with a bit of black pepper added. "Little Lucy" Okra can also be patio-grown. The plant and its purple pods are beautiful and the pods stay purple when cooked. (Yes, that does get raised eyebrows and I know not everyone likes okra!) There are many varieties of Mid-Eastern cucumbers that have very thin skins and few/no seeds. And there is Thai basil - I like the purple-leafed variety, but there are many others. I think herbs in general deserve a place in a patio garden.
Thanks for reminding us you don't need an acre to have a "comestible garden."