Emirates is one of the best ones to travel with children, I have seen them take special care for young ones. If you are travelling to the west coast (like Vancouver), Singapore would be best followed by Cathay Pacific. Etihad could be next best option followed by Swiss Air, Jet airways and Lufthansa, in that order. The experience with Air India can vary a lot, but I seem to like them actually. Same goes for British airways, but I personally hate them. Definitely avoid KLM/Air France or FinnAir, they are consistently bad!