Two more for the plant and forget list:
Ginger and Horseradish.
Sure, they aren't veggies per se, but you'll be glad to have them. Ginger, apart from having the most wonderful taste, is good for everything from colds to arthritis. Horseradish is a nice source of heat in a dish if you don't have pepper or mustard kicking around.
Both are easy to grow, indeed horseradish will make a determined bid to take over the county if you don't restrain it a bit. Ginger needs a little help with overwintering in all but the mildest climates, but a thick layer of straw is enough to keep it viable.