Hi, Carrie! I think the best is one that really shows off the themes that Walt Disney World is so great at creating.
Disney's Art of Animation Resort is great for kids. They bright colors and being surrounded by familiar characters makes every inch of this resort a head turner. They have an awesome food court, Landscape of Flavors, which offers a great variety of quick and delicious meals.
I also really love the Royal Guest Rooms at Port Orleans Riverside. These specially appointed rooms will make you feel like you've stepped inside a castle created for Princess Tiana, complete with a private "fireworks" show, right from you bed every night. It's also got a great pool area for young children.
If you want to go all out on this trip, consider one of the deluxe monorail resorts. The Magic Kingdom view rooms at the Contemporary Resort, the Polynesian Village, or the Grand Floridian all the monorail convenience, plus the bonus of seeing the fireworks from your room each night.
Have a great time choosing!