Yes I agree JK - of course we have SUPERMAN and so on.
What makes DOCTOR WHO more compelling is the spiritual quality which is being applied to him.
Yes we all need a Saviour - Gordon Brown has tried to put himself forward as Saviour of the World recently....without success.....but DOCTOR WHO embraces many of the Theological elements that point to a true Messiah.
I would therefore contend that DOCTOR WHO is the Messiah unless someone can correct me with another figure from popular culture who has more of those qualities.