Sunflowers
Helianthus annuus from the Asteraceae family. Related to daisies, chamomile, black-eyed susans, golden everlastings, et al. Native to the Americas.
I diverge slightly from the fruit and vegetable theme here with the sunflower. While its seeds are eaten and the oil made from said seeds is widely used, I don't think it's considered a fruit or a vegetable by many. In fact, I grow them for one reason only; their big, brash yellow flowers.
The particular breed I bought is Yellow Empress from Yates. I can't say I'm too impressed with the seeds, as half of them I've tried to grow have been duds. Yes, the soil is good and I followed instructions.
However, I've got four growing, three of which are flowering at time of writing and the fourth is developing its flower head. Popular canon says that the flower head of the sunflower will point to race east. I haven't seen this behaviour yet. One is pointing due west, and the other two are facing a rough north-westerly direction.
Alas, birds have attacked two of them, which is their wont, I guess.
I don't have a scanner at the moment at which to scan in photos of my own plants, so I've leached the photos found at Wikipedia's entry for the plant. These pictures are copyrighted under the terms of the GNU general public license and are not my own.
In summary, they're a simple plant to grow (assuming your seeds germinate). I have noticed a little wilt here and there, but that's nothing a good watering didn't fix. Once those delightfully huge flowers open, you'll be glad you've grown them.