I always like to include a few zinnias in my garden. They're a great attraction for the butterflies and they hold up well in a bouquet. Right now, I have a lot of pink ones blooming.
The Black-Eyed Susans are starting to open now, too. I did not plant these myself; they were a welcome leftover from the person who had the plot prior to me. They were one of the "surprise" perennials I discovered in my first year at the garden.
The blue sage plant has been providing a steady profusion of blooms since May. I always have plenty for cutting.