"Aloha. Aloha, suckers" was just one of the many catch lines Jack Lord's character "Steve McGarrett" used. In the series, "McGarrett" was a former U.S. naval officer who was appointed by the governor of Hawaii, and only took his orders.
After the success and ending of the series, Lord remained quite low-key in the entertainment industry, and was diagnosed with Alzheimer's soon after. He died on January 21, 1998 at his home in Honolulu due to congestive heart failure. He was 77.