Regarding transfers from French airports.....
VEA bus is the official Disney transport, with services from CDG, Orly and Beauvais. They are more frequent from CDG, and stop at the 6 Disney owned hotels, but not always the non Disney ones. Guests staying in one of these may have to get off at the bus stops by the Village and Chessy station, then catch the free shuttle bus to their hotel. It depends on arrival/ departure times.
VEA bus charges per person for adults and kids aged 3-11, so a private transfer can work out cheaper and easier with kids and luggage. Private companies charge ? 65 - ? 70 each way from CDG or Orly to Disney. Beauvais is more expensive as a longer distance. The advantage of private transfer is that they will meet you at arrivals, and you can be straight on your way directly to your hotel. The VEA bus stops at hotels in order, so takes longer if you are the last one! You could also be waiting for some time at the airport, after having got to the VEA bus departure point, for the next bus.
Three companies are used regularly and recommended on the TA DLP / MLV forums - links are given in this thread about transfers from Orly to Disney.
www.tripadvisor.co.uk/ShowTopic-g187147-i14-k4555953-Paris_Orly_Airport_to_Disneyland-Paris_Ile_de_France.html
Also see this thread, and others regarding transport in the Top Questions list.
www.tripadvisor.co.uk/ShowTopic-g226865-i2224-k4499841-l33518923-Anyone_used_tge_private_transfers_for_eurodisney-Marne_la_Vallee_Seine_et_Marne_Ile_de_France.html
You will find info about the fast TGV train which takes 10 mins from CDG airport to Disneyland, but this depends on your flight arrival time, and is quite difficult to estimate how long it will take to collect your luggage, then get to Terminal 2D where the TGV station is situated. The cheapest tickets are called Prem, but these cannot be used on another train if you miss yours for any reason. You need to purchase tickets for a particular train in advance, especially if travelling around school holiday time.
Then once you have arrived at Chessy station, you have to get to your hotel either by walking, or using the hotel shuttle buses as long as you arrive during operating hours.
For me, private transfer is the best option for arrival, and you can consider others for return, when you can be sure of catching a particular TGV train from Chessy, or VEA bus as an alternative to private transfer both ways.