There is something to be said for an irrefutable theory: It can't be refuted.
[This isn't quite a tautology, because "There is something to be said for" has a valuative component that does not tautologously follow from irrefutability. Anyway, I am always amused when I see the move made against Intelligent Design in public debate: "It's irrefutable. And besides, the evidence is against it." It seems to be like the case of the man who complained that the food was revolting and the portions too small. (I am assuming that "refutable" means something weaker than "can be apodeictically disproved", since coherent scientific theories tend not to meet that standard of refutability.)]