I thought the children in Rabbit Proof Fence were great, especially Sampi(?), the oldest girl.
I usually don't like child actors since it never really comes off, especially in N. American films because every one is conscious of making them cute which in the end makes them weird.
I find the kid from AI a rather mannered actor for his age and watching him makes me very uncomfortable,which may have more to do with Speilberg's direction.
The one kid I liked was the little girl in Enough. She was almost as good as Danny in the Shining, truly cute, no sugary stuff shoved down your throat and a real child with that spontenaity or vulnerability that any professional loses no matter how young.