Try a Night Blooming Cereus/Orchid Cactus. They only bloom at night between 8pm-midnight. The blooms are as big as a dinner plate (9-10 inches) and will fill the entire house with their fragrance. Not everyone likes the fragrance though. I found the scent not unpleasant but was somewhat of a chemical smell. Unfortunately I do not have a good picture of the plant itself although you can see part of it in the window shot. If you google Orchid Cactus or Night Blooming Cereus you can see the plant. You can see the bloom next to the ruler that the bud just before opening is 5-6 inches long. When it begins to open around 8 ish then it opens really fast over the next hour and you can almost see it unfurling.
