I cannot say enough good things about Emirates. I typically fly Emirates between Dubai and India, an international flight although only about three hours long. The experience from beginning to end is always stellar.
First of all, online reservations can be made for children, including babies, and the entire system is well organized. You can check multiple people online at the same time and then email your boarding passes to one email. Small things that make things convenient. The system is intelligent enough to know that I booked an infant and automatically assign me a bassinet seat.
In-flight, the entertainment system is top-notch with personal TVs, and a host of channels showing programs/movies for children. You can also play games or listen to music.
In addition, the airline always offers a coloring book or little toy to welcome their little travelers on flights.
The kids’ meal is always tasty with a little snack box you can hang onto in case the munchies come on a little later.
Finally the service is always great, with the flight staff warm and welcoming to children, as opposed to looking at them like they are the worst thing that could be on a plane, a big plus in my opinion.