1- Jose Mourinho
The Special One may or may not have cried at the appointment of David Moyes, but it's of little relevance in the long run.
The plain facts are that United made a stinker of a decision in not offering Mourinho the job.
The Portuguese manager is rigid in his methods and does like things done his way, but those downsides are usually balanced fairly in the fact that he more often than not guarantees trophies and success.
Only Mourinho knows if he would have taken the United job over a return to Chelsea, but from the outside looking in it appears as though United should have given him the option to choose.
He has title-winning experience in multiple divisions around the world, including the Premier League, and his presence offers any team he manages an immediate advantage over their positional rivals.
Put plainly, Mourinho could have been the perfect man to have succeeded Ferguson, and was the obvious choice.