I grew up listening to The Voice of Prophecy. I loved listening to the King's Herald's Quartet that included Bob Edwards, first tenor, Bob Seamount, Second tenor, Wayne Hooper, Baritone and Jerry Dill, Base. They sang during most of my childhood. I always thought they sang so well together. I am sure all the other groups are great too.
I enjoyed Elder H.M.S. Richards sermons. I was also blessed listening to his son HMS Jr. who was a dynamic evangelistic speaker. Later he joined his father on the radio vop programs.