Larry King hitches up his suspenders for one last show Thursday, as the television legend broadcasts his final interview on CNN. King's career has spanned five decades and included 50,000 interviews. Larry King Live bosses are keeping King's guests a secret for Thursday’s show. Comedian Bill Maher and American Idol host Ryan Seacrest will be on hand but 14 mystery guests are supposed to join King for his final hour. King has interviewed every president since Richard Nixon. Still he's known for his dexterity, welcoming everyone from Lady Gaga to Bill Gates to his set. King got his start in radio at 23. The 77 year old joined CNN in 1985.