My second favorite flower would have to the dahlia. Here are a few of them. These guys grow from tubers which can over-winter in zone 6 as long as they are well protected, and I use leaf filled bag to protect mine instead of digging them up and bringing them indoors which is too much work.
Here are the results.
Angel wing begonia: I bring this one in every winter, and it blooms nonstop
One of my sedums: I have over 20 species of sedums, some that get tall like this one, while others are ground covers.
Long bean blossoms
Luffa gourd: This stuff blossoms by sunset, and they tend to fall off early in the morning
Those are all male flowers up above. Here are the actual gourds. This is very prolific as 1 plant can can produce around 30 gourds a week with ideal conditions. They get up to around 2-3ft long by 2 inches, but they are best harvested by around the 2ft mark when they are still relatively skinny because they turn bitter if they mature, and produce seeds.
The vines from the stem can cover perhaps 1000 square feet of space or more if there is an infinite amount of room, and the stem gets fatter and fatter throughout the year. This stem is still relatively skinny now, but it should grow to be fatter than the 1 inch thick pipe next to it by the end of the year. This is why this vegetable is so productive. This vegetable is great for stir-fry, or soups. It is basically Chinese Okra, and gets used for the same purposes as broccoli.