The broad trumpets of cup & saucer vine are an enduring curiousity Summer to frost. They all open creamy white, as here. Those of the straight species quickly darken to grape-purple, whereas these of the 'Alba' form stay bright.
I vote for 'Alba', because the blossoms are showy even from a distance. Thank goodness: Even when grown as an annual, this vine can grow so large that it lends itself to large-scale effects that are also showy from clear across your garden.