Jose Mourinho: The sure thing. There's no doubt that he would bring success and trophies, while he clearly gets on with Ferguson and would have no problem working in his shadow. They are, as we saw when United played Real Madrid, best buddies. Against that, he's not been endorsed by Sir Bobby Charlton and has no history of Ferguson-style endurance at any of his clubs. And will his confrontational style just be too much for United too accept? Can he bring through and develop youngsters in the way Ferguson has? Does he want to?
David Moyes: First of all, he's Scottish. That works in his favour big time. But then so's Alex McLeish. Perhaps of more relevance is the magnificent job he has done at Everton in the past 11 years, making them a consistent presence in the top half of the table despite having little money to work with. He's also shown a keen eye in the transfer market - Phil Jagielka, Tim Cahill, Marouane Fellaini - and has brought youngsters through. But he's never managed to break the glass ceiling or win a trophy, while there are doubts over whether he's positive enough.
Jurgen Klopp: It's fair to say he knows how to build a team - but the one he's built at Dortmund is about to be decimated. Could he be tempted? It's hard to make an argument why he shouldn't get the job, actually. It's more whether he'd want it.
Ole Gunnar Solskjaer/Ryan Giggs/Gary Neville: All United legends, though none have much experience. Only Solskjaer is a manager and he's done well at Molde.
Mark Robins: Ferguson owes him.
Phil Brown: If there is a God.
What do you think?