Pete's Dragon - the 1977 version. It was the first movie I recall going to an indoor movie theater to see.

However, it was more common for us to watch movies at the drive-in. Our parents would take us to the local drive-in movie theater to see movies as a family, because we didn't have a lot of money for entertainment, and it was $5 a carload to get in, so it was a cheap way to get everyone a night of entertainment. No trips to the snack bar for us, though - Mom took care of that before we left the house. She would pop a big batch of popcorn, toss it into 2 doubled paper grocery bags, throw in some melted butter & salt & hand it off to one of us kids with the top of the bags folded down to shake it up. Then she'd boil water and dump it into the big old thermos jug with the wide-mouth lid - then she'd pop a couple packs of hot dogs in the jug and seal it up - the hot dogs would be steamed and ready by the time we wanted to eat them. A separate thermos jug of cold Kool-Aid was next on the list. Then she'd pack everything up, including all the condiments, buns, potato chips, paper plates, napkins, plastic cups and the food, and off we'd go. We kids would be dressed in our PJs before leaving the house, so we could just be dumped into bed when we got back, without having to be awakened, because it was certain we'd be asleep before we left the drive-in, because it was always a double-feature, so we'd be home late. We'd play on the playground equipment directly in front of the gigantic movie screen until the previews started, and then we'd race back to the car - a big old station wagon - to take our spots on the roof and watch the movie while we enjoyed the food Mom had brought.

I saw my first R-rated movie on one of those drive-in trips - my parents didn't realize I was still awake and watching the 2nd film of the double feature - it was The Wanderers and I was about 8 years old.