1. Movies- Hercules, Lion King, Little Mermaid, Beauty and the Beast, Hunchback, Toy Story... the Disney movies of the 1990s were what DD was raised on and we have incredible memories from enjoying them together. Some of the songs still make me cry when I think of DD and my 2 nieces, growing up together.
2. WDW live entertainment. They are pretty lacking right now, having phased out so much, but Festival of the Lion King is spectacular, and I adore Beauty and the Beast. I very much miss Tarzan Rocks and Hunchback- what amazing productions! It's sad that they've let the "lesser" entertainment lapse, like the Citizens of the Streets of America (I think that's what they were called, at the Studios). Disney certainly knew how to do live, in-park entertainment for a while there.
3. As others have said, just being there. Knowing that I am someplace that will amaze me, that I know well enough that I can relax and not worry about everything that might go wrong or that we might miss. Even though going to WDW can be stressful, once we get there I am filled with a sense of peace and can relax... after all, I'm Home!