Thanks to TBF for the suggestion. Here are mine:

1. Glenn Frey
2. Don Henley
3. John Lennon
4. Paul McCartney
5. Van Morrison
6. Mick Jagger
7. Bob Dylan
8. Robert Plant
9. Elton John
10. Mark Knopfler /Neil Young (tie)

I realise that Dylan's singing is not for everybody, but I cannot leave him out. As for Knopfler, ditto, but although he may not have the most 'tuneful' voice or a great deal of range, I defy anyone to hear him sing Romeo & Juliet and not get a lump in their throat.

Honourable mention to Randy Newman, whose singing also is not for everybody, but he does it for me.

My favourite female singer is Kate Bush. There is nobody like her, although I agree with Rolling Stone about Aretha. I don't think I can do a Top 10, at least not yet.