Get a Park Hopper pass and have fun. It's so for adults too. Magic Kingdom is for adults but does tend to get more attention from the little kids than the adults. I recommend park hopper because if you're an animal fan you should check out Animal Kingdom or if you're a big time movie fan try out Disney's Hollywood Studios. Lots of stuff there for us big kids. Epcot finishes off the evening well. If you've done the other three parks before you'll probably hit your favorites and have time to see a little bit of the world. Take one of the ferries and enjoy some of the best restaurants in Epcot like the one in Italy or France. Add in Illuminations at night and it's a romantic evening for two.