The best annual flowers will vary from one part of the United States to another.
Therefore the selections for your particular area should be arrived at by meeting with a well informed horticulturist.
Another option is to contact your local university extension office who can offer very good advice.
We have developed several lists of annuals that will perform extremely well in zones 6, 6B and 7.
Many of these annuals will do very well for you regardless of your location.
Our selections can be found under the following links: Types of annual flowers and Summer annual flowers.
Be sure to check the first link for our choices for fall and winter color and the second link is a guide for spring and summer annuals that are the most reliable.
Be sure to visit the full sun and shade annual flower selections.
From Best Annual Flowers to Annual Flowers