Some possibilities include oregano, sage, thyme, savory, marjoram, and all varieties of basil. You don't need to dry herbs or their flowers before you use them-in fact, they are tastier when you use them fresh from your garden or your local farmer's market. Blossoms are often the best part of the plant, containing most of the essential oils. This makes herb flowers sweet, fragrant, and flavorful. There are many other edible flowers.
Some examples follow.
Most people pull the plant and use it when it starts to send up a flower stalk. Some chives produce blue flowers that add a pretty blush with an oniony taste. You can use those tops and flowers in several ways. Try making a tangy sun tea by filling a clean glass jar with bottled water. Then toss in a couple of tea bags, and add a handful of Cinnamon or Anise Basil flowering tops.