Well, Dante is more destructive and much more faster.
Ciel on the other hand has literal immortality and regeneration-negating equipment. Unless Dante has some way to permanently keep Ciel down, the later would win by simple matter of exhausting the Demon Hunter.
As for Sayaka vs Shirou: Well, hard to say. I side with Shirou due to the more versatile weapons at his arsenal.
Sanji vs Shirou? Shirou is just a good cook but Sanj is supposed to be a master. Well, that aside I really don't know.