You will have the choice of three character meals:
Cafe Mickey - Lunch & Dinner
This will be the most reasonable priced character meal - Cafe Mickey is located in Disney Village and there will be characters out there each day for lunch and dinner. I find the character interaction here to be good - although you tend to see a lot of the same characters that are out all the times in the parks (Mickey, Minnie, Pluto etc...).
Auberge de Cendrillon - Generally Lunch only
This resturant is in the Disneyland Park and is the only character meal where you will get to meet the Princesses (and the mice & a prince!). The menu leaves a lot to be desired though and the prices are quite expensive. But if your children are princess fans this is a must do!
Inventions - Dinner Only
This restuarant is located in the Disneyland Hotel and is a buffet meal for dinners only. The prices are very high, but the food is of a good standard and there is a good selection. If I had to choose one Character meal to do, this would be it - the location, choice of food and character interaction make it a must do in my books!