I took my 9 and almost 6 year old to see Toy Story 3. I loved it as did my 9 year old, but I was surprised that my almost 6 year old actually got really scared when the toys were at the landfill, heading to the fire. She was crying, she was so scared. Guess this is something to keep in mind for young kids.
I took my four year old to see Bolt. I thought the movie was really cute, but my four year old had trouble following the plot. She got very restless in the middle. I think that 5-10 years old would be the ideal age.