Akebia quinata
There are some plants which I would always make room for in my own garden, no matter how small that garden might be; and Akebia quinata is one such plant.
It is a vigorous, semi-evergreen, twining climber which is great for covering walls or old tree stumps and if left to do its own thing will happily climb to a height of around 12m in a tree or large shrub. I prefer to grow it on the wall next to the front door, so that I might experience a whiff of its scent each time I enter or leave the house during its flowering season.
This comes in April, the flowers hanging in racemes from the leaf axils of the older growths. They are very fragrant, although sometimes their scent can be elusive - undetectable at close range but very strong at a distance. Each flower is either male or female, and in the best selections they are a luscious plum-purple. I have come across plants on which the flowers are much duller, almost a dirty reddish-pink. If you are tempted to have one in your garden, my advice would be to buy one in bloom so that you can judge the quality of the flower colour.
An added bonus which occasionally crops up is the production of edible fruits. These ripen to a deep purple, are sausage-shaped and between 5 and 10cm in length. Cultivation is pretty straightforward, the plant seemingly unfussy about soil type and being of both sun and shade. However, if you want to taste those unusual fruits it would be best to provide your plant with a southerly aspect as warmth and plenty of sunshine are required for ripening.