Disneyland Paris is a must for families, at least once in a lifetime. More privileged families visit it very often. It is a small city with parades, colorful characters, tiny houses and a lot of things to do including thrilling rides. In regards to accommodation, it all comes down to budget...
If you are planning a one day visit then you can stay in Paris and take the train for Disneyland. If you are however planning to spend a few days in Disneyland, then it is better to stay at one of the nearby hotels.
The most expensive, 5-star hotel owned by Disneyland, is the one which sits at the entrance of the park. It is called Disneyland Park hotel and it is the elegant pink building which looks like a princess castle. It could cost you around €600 per room though to stay there, but that includes tickets and unlimited fast track access, which is pretty awesome when there are long waiting lines at the rides.
Then, there is a 4-star hotel which is huge, named New York and is about 5’ walking distance from the park. It is less expensive and less refined though, but it has a nice lake view.
There are many other 3-star Disney hotels in the area including the 3-star, Disney’s Newport Bay Club with lake view as well and Disney's Sequoia Lodge.
For more info check out their website.