That depends on when you will be able to get to the park. I would happily suggest just going for the fireworks and parade. (I suggest walking right up the stairs to the train station balcony as soon as you go through the entrance tunnels.) That way, if you're at MK later in your trip, when the parade starts, you will have already have seen it. Then you will be able to get on a lot of rides with very short waits while everyone else is watching the parade and the fireworks. Just keep in mind that you can't cross the parade path once it starts. You can either confine yourself to Adventureland, the south side of Frontierland/Liberty Square(Country Bears' side of the road), and the west side of Main Street (Crystal Palace side), or you can get "behind" the castle. Here you'll be able to get to Tomorrowland, Fantasyland, the north side of Frontierland/Liberty Square (Haunted Mansion side of the road), and the east side of Main Street (Plaza side).