Here is a "fun" question
What band/singer/whatever would you like to lead the music?
I wouldn't choose one. A 'celebrity' group would take the focus off the worship of God and become more of a performance - at least in our church, where in general we don't have 'worship leaders' at all. If I want to hear a particular group sing a particular hymn or Christian song, I'll listen to them at some other time, without the congregational singing getting in the way of the sound; if I want to worship in church, I'll sing without the distraction of a bunch of famous people up the front.
I wanted to clarify that in my church, our worship time together is not about worshiping any deity. I would not actually want any of the aforementioned celebrities to lead our worship- It would take away from the sanctity of worship and be more of a "show." In the past, people have lead the congregation in singing Beatles or Woody Guthrie tunes. I was thinking more along the lines of famous musicians whose music I'd like to sing along to during worship.