We have done them all when it comes to Princess Dining.
Even though others have recommended Akershus, and we loved it too, it really doesn't compare to a couple of others: CRT and 1900 Park Fare.
For CRT, the castle setting just can't be beat. Sure, it's a bit more expensive, but that's just how supply/demand works. If it weren't great, there would be less demand, and lower prices. Two times we have gotten the very first lunch reservation and it has been perfect. Not only is there no waiting to get in to see Cinderella, but the dining room doesn't have a busy feeling to it. Last time we were there they changed how they let people into the restaurant, making it MUCH less busy as you exit. Less busy enough that Cinderella didn't have anyone waiting to see her, so she gave a personal escort out of her castle to one of our girls.
For 1900 Park Fare, again, the very first dinner reservation is a good idea. If you arrive extra early you have a very good chance of being the first one waiting by the door and have a very good chance of a personal escort into the dining room by Cinderella and her Prince. Only happens once per night. Then, once per dining block, Cinderella and her Prince will come out to dance together. Be ready to have your little princess near her and she will have a personal dance with Cinderella. Most diners don't know this will happen, we didn't the first time, so there will be little to no "competition" to this special dance.
You certainly can't go wrong with Akershus, but in my opinion it is there for meet and greet purposes only and there are really none of the special "extras" that make the other places special. The princesses do take their time (no more than CRT though, in my opinion) and it's great to meet them all and get pictures. The ADRs here are also easier to get.