When my son was in early elementary he was very sensitive and had things he would NOT watch. The main example was "Charlie & The Chocolate Factory". The Johnny Depp version has just come out and advertisements were everywhere. Both movie versions, the book, and even didn't want to see the movie cover. He even got in trouble at school because of this.
Because of this I was careful what movies to let him see. At around the same time he saw a photo of ET and became very fascinated. I ended up watching it with him and he had no problems. I really had a hard time figuring out what would bother him and what wouldn't.
As to what is appropriate. Best thing is if you have watched a movie already, or watch it with them. My son is a teenager I'll let my son watch almost anything as long as my husband or I watch it with him.
