I also vote for the DVD player. We had 3 children under 4 so I needed anything that would keep them quite. This was for the other passengers sake as well as mine!

I also tried to travel during their nap time and usually didn't fly more than 4 hours. If we had lay overs we let them run around and tire themselves out. We also had the books, colors and of coarse snacks.

When our daughter was young I used to record myself reading her favourite stories, she could the listen to a familiar voice through headphones thus not disturbing other passengers. I would also secure a cord onto a toy which could then be looped on the seat belt, making it easy to find.

Everyone has had great ideas. When my now 17 yr, old and 12 yr, old were little, I would buy cheap safe toys from a place like big lots, wrap them up and put them in a little cheap backpack. Every 30 minutes we would pull something out like finger pupperts, small cars, puzzles etc. and unwrap it and play. My ultimate weapons were lollipops and those old-fashion candy dots on paper. It would take them forever to peel the candy off the paper but it kept them entertained. I also brought a tooth brush and toothpaste and had them brush their teeth,

Finally I alway made sure to have water and snacks. Sitting on the runway in Chicago in a heat wave, the water saved the day during one trip. I would never have brought along that much junk as the op mentioned. too stressful.

I, too, did the 'big lots' cheap-o gifts every 30 minutes, but the biggest hit of all was a box of "pipe cleaners" from the craft store. My husband (the engineer) was quite talented and the variety of items made included airplanes, eyeglasses, and flowers which were given to the flight attendants. Best 99 cents I ever spent.