The idea of couple-time on a family trip is a lot more plausible, now that virtually all hotels and resorts have kids clubs. Many places offer a "Kids Night Out" as well.
Click below for suggestions such as the Hotel Hershey in "Chocolate Town USA", where kids can make chocolate art, and grown-ups can sample the Chocolate Spa. Or try a luxury resort in Orlando that has an evening kids' club, or an all inclusive resort in Florida that has terrific kids programs, or a lake-side resort seventeen miles from the Las Vegas strip...
#1. Disney World Deluxe Resorts
All the Disney World Resorts -- Deluxe, Moderate, and Value-- are great for families, and confer great perks such as Extra Magic Hours in the theme parks, use of the convenient Disney Bus system, and more. But the Deluxe resorts have a special plus: a kids' club on-site. Typically, it's open in the evening, with games, craft, movie, and comfy place to nap.
Animal Kingdom Lodge, for example, has Simba's Cubhouse; this resort also has African animals in the savannah outside, family activities, storytelling by the firepit, amazing architecture.
Likewise, the Grand Floridian Resort & Spa has a kiddie hangout called the Mouseketeer Club, and the Polynesian Beach Resort has The Neverland Club... Check out these and other Luxury resorts at Disney World Resorts by Type. You might also have a look at Disney World Resorts by location, honing in on the tree Deluxe resorts near the Magic Kingdom, for example. See also an overview of kids clubs at Disney World Resorts.