This may not be the type of "special" you're looking for, but I would highly recommend a mother/daughter or father/daughter evening out. I see you have five children, so getting to spend some time alone with one parent doing whatever she wants might be a huge treat.
I started this tradition with my oldest during our first trip. She was 9 and the younger two were preschool aged. We picked one evening that was EMH at MK where just she and I went out together until 1am. We didn't do anything extravagant, but we both still have wonderful memories of eating ice cream while people watching and riding BTMRR during the fireworks. It's just nice to be able to relax and focus on one kid rather than consider and compromise for the whole group.
This was such a special tradition for DD that during our last trip (she's heading to college this year) she took each of her siblings out one night to have some individual bonding time, go to whatever park they wanted, and eat whatever snacks they were in the mood for.