For me it's hard to pick just one but for lack of a better example, I'm going to go with David Bowie, and a couple of these aren't technically questions but you get the point:
In no particular order:
1. What was it like doing Labyrinth?
2. Explain 'When I'm Five' to me
3. Do you get asked about your eye a lot?
4. Following question 3, is it uncomfortable? (yeah I know it's rude but that's me)
5. Didn't you ever eat in the 70s?
6. What was it like doing Dancing in the Streets (music video) with Mick Jagger?
7. 50 cigarettes a day, how the hell can you even still talk?
8. What's with the mime thing, and why so tight lipped about it now?
9. What in the hell was with the clown outfit in the Ashes to Ashes video?
10. Just for clarification, explain the whole faschist thing to me.