I'll have to give a range of options too.
If money is no object, then Napa Rose in GC is considered one of the best restaurants in California - but it will also cost you up to $200 for 2.
If that money is out of your price range (as it was for us) then Blue Bayou is a good experience - decent food, great atmosphere, great service and inside the park (and inside a ride too!). We really enjoyed it, and because t was inside the park found it very relaxing.
BUT - if you asked my kids, they would say Rainforest Cafe (In DTD) which they adored - again, decent food and a brilliant atmosphere.
And DOUBLE BUT - Character breakfasts are fun too - we did the Princess breakfast (we have girls aged 9 and 6) and that was a lot of fun, though the food was pretty ordinary and others have complained here about having a bad time there).