Like Mo, we live too far North for driving/Eurostar to be a viable option, so we flew.
I shopped around and British Midland fly from Leeds Bradford to Charles de Gualle for £60 which I thought was quite reasonable.
We caught the bus from CDG to DLP and while it's easy enough, I thought it took a very long time - we spent a long time driving around the airport to various terminals, then the drive to the park, and then another trail around the hotels at the park - all in all it took over an hour, maybe an hour and a half.
I have heard that you can get the TGV train direct from the airport to the DLP, but have never worked out exactly how to do it -
If we went back I would look into this further, or take a taxi, but I would be loathe to take the bus again.
Bev