You mean I can pick only one?... Well I guess I'll go with a very cliche one. The first time I took my daughter. She was 8 at the time. I took her up a few days before my new fiance and her family were to meet us up there. Just seeing her face the minute we got to Pop Century and the excitement in her voice on the car ride up made a big impression on how much it meant to her to be going. Of course the jaw drop when enterring the Magic Kingdom staring in awe at Cinderella's Castle was not to be missed. Riding all the rides and seeing all the shows of movies that we've watched together. Taking the smile off of her face was impossible. Then the rest of the family arrived and she got to have some fun with kids her own age, not just her big kid dad. There was nothing in the parks we didn't do. I know that's her fondest Disney memory too, since she hasn't stopped talking about it (keep in mind this was over two years ago) and wants to go back with me soon.