If you have young kids (especially horse-crazy ones), Secretariat is a good one for the kids. Interesting story about the horse, great racing scenes, no inappropriate scenes for the little ones.
Heck, I KNOW that the horse won the Triple Crown and my heart was still beating fast during the racing scenes. Some of the photography was amazing!
Both my 6 year old boy and 10 year old girl loved it. The boy thought it was like race cars, only horses.