Cup and Saucer vine (Cobea scandens) is nice. Blak-eyed-susan vine (Thunbergia) is another one. Is there a reason that you want only annual vines? There are a lot of perennials that would also work. Wisteria of course, and Clematis are very showy.

I want annuals for two reasons: (1) I might grow some in pots, and (2) I want to change them out for variety. Later I'll settle down and get a good ol' faithful perennial.