My first thought to this is "Oh dear Merlin, don't let Dudley be a Slytherin." I personally don't think he would be, and I'm not going to take time at the moment to look up reasonings to back up either Hufflepuff or Gryffindor as a sorting for him. This also leads to the thought of how wonderfully different the books would have been if Harry had been sorted Slytherin. We certainly wouldn't be looked at in the same way.

Morgan//Slytherin//4