I don't think Kakashi dislikes Naruto more than anyone else in the team.

Kakashi usually don't smile. And I don't think he has smiled directly at either Sasuke or Naruto.
The reason Kakashi focus to train Sasuke is because he knows how to make sasuke more confident and strong just because he is like him. If naruto would have been trained by him, he would probobly not be as strong as he is now.