I insisted on a geranium. They are so dependable and forgiving. My grandfather used to keep geranium "trees" in his green house all winter. When I first went away to college he gave my my own geranium tree for my dorm room. Ours was a bit sparse when we bought it, but has adapted well to potted bliss.
We also have a begonia, which is bursting out of its container, some struggling snap dragons, and other decorative species.
But my babies are the herbs. The basil, lemon basil and rosemary I rooted from cuttings given to me (Thanks Toni!). We bought the parsley and chive plants. The chives are now occupying my abandoned violet pot. They give me something to nurture and harvest for soups and sauces, and since I am deep into Barbara Kingsolver's Animal, Vegetable, Miracle, it also makes me feel a bit closer to local sustinance. The Jersey tomatoes (Diane has gifted us several delicious heirlooms), corn and peaches, combined with the local seafood make me feel somewhat satisfied with my localized eating. And I'm sure my balcony herbs are properly stressed, growing over a busy (relatively speaking - we are on an Island after all) traffic light without any pesticides.