I'll have them once in a while too. One of my favourite ones was prior to the last two times I was there. My wife hadn't been yet and I had been prodding her about the place (she was skeptical, we laugh at it now).
But in the dream I could see the castle from a distance, within walking distance. It was similar to the way in the Wizard of Oz when Dorothy and them see the castle for the first time and then run through that patch of flowers to get there.
Except it wasn't flowers, but a really big hill for me to climb. My wife was with me and I kept encouraging her to move along. When we entered the gates it didn't look like the castle at all there but I knew it was Cinderella's Castle for some reason. I felt peace, happiness and everything that I feel when I am there. Then.............I woke up. A few months later we went there for real.
Another dream is being on a boat ride, I can't figure out for the life of me if its Small World, Splash Mountain or what, but its peaceful and I know where I am even if its a little sketchy to make out the details. It is a little bit of torture when I wake up for real.