The unquestioned star of the late summer show in my yard is Butterfly Ginger (hedychium coronarium.) The snow-white bloom clusters on top of lush, strap-like foliage says "the tropics" like nothing else.
The plant looks something like a corn stalk. I like them growing close to some sort of support because they can get top heavy and flop over. They get around 5' tall. I think they would look great at the back of a tropical bed along with some cannas and banana trees.
The flowers put out a fragrance that is intoxicating and will fill the whole yard on a summer evening. I have them stategically placed around my yard so as to really get good scent coverage. This is one of my favorite fragrances of all time - it's very similar to a gardenia smell.
These plants spread very readily from the roots and eventually will form a large grove of stalks. There will be plenty to share in just a few years. They do not take drought very well and will not survive winters north of about zone 7b unless really protected. Mine die to the ground each winter only to return better than ever in the spring. I have them growing in everything from shade to full sun. The ones in full sun need more water and don't look as happy as the ones that get at least some shade. Every Louisiana yard should have some of these.