The world's greatest athletes have all gathered in Rio to compete in the 2016 Summer Olympic Games

The 2016 Rio Summer Olympic Games officially opened Friday, April 5. Four years ago U.S. athletes won 103 medals at the Summer Olympics in London. As of Sunday, August 14, the U.S. has won 66 medals, including 26 gold medals. That number is sure to increase. What athletic feats or performances have impressed you the most? What are your favorite competitions to watch? Do you have any special memories from past Olympics you'd like to share? We'd like to hear from you.