French Marigolds (tagetes patula) are well-known as perhaps one of the best additions to flower and herbs gardens due to their wonderful ability to repel unwanted bugs and pests.
The odor that their blooms give off are offensive to many common garden parasites and will aid in keeping your lovely garden easier to maintain.
Use caution when planting in excess, since marigolds have an unfortunate tendency to attract spider mites and snails.