Today marks what would have been Elvis Presley's 80th birthday, and thousands of fans from around the world are gathering in Memphis, Tennessee, to attend special events that have been scheduled to commemorate the milestone at the Graceland estate and around the city. One of the main highlights of the celebration took place this morning on the Graceland lawn, where a ceremony was held, declaring Thursday to be Elvis Presley Day in Memphis. With Priscilla Presley on hand for the celebration, a specially designed birthday cake was also cut/ABC News. More here. (AP file photo)

Question: All-time favorite Elvis Presley song?