I see the BBC has another list ranking 20th century Prime Ministers, with Clement Attlee and Margaret Thatcher not surprsingly coming out on top, Neville Chamberlain and Anthony Eden at the bottom, and Tony Blair somewhere in the middle.
I reckon that's probably about right, although I would rate Churchill higher than Thatcher and both James Callaghan and John Major higher than Francis Beckett does - both were dealt an impossible hand by their small parliamentary majorities. I also think he rates Harold Macmillan far too highly - the man was essentially a poseur who allowed Britain to stagnate under his seven-year leadership.
Meanwhile, as my contribution to the debate, here's my list of the Top 10 20th century figures never to become Prime Minister. Or at least, in one case, not yet.
1. Denis Healey
2. R.A. Butler
3. Hugh Gaitskell
4. Joseph Chamberlain
5. Gordon Brown
6. Enoch Powell
7. Iain Macleod
8. Michael Heseltine
9. John Smith
Not all of these men could realistically have become Prime Minister - three of them, Gaitskell, Macleod and Smith - died before they had a real opportunity. But some of them would have done a far better job than the men they were forced to give way to - notably Healey (Callaghan), Butler (Home), Brown (Blair) and Heseltine (Major.)
Enoch Powell is of course the great enigma in my list. Had he, rather than Heath, won the Tory leadership in 1965, would "Thatcherism" have arrived 15 years earlier? Probably the country wasn't ready for it then, and might never have been ready for Enoch. But a genuinely great man nonetheless.