When choosing a family-friendly hotel, sometimes it's less about "what" and more about "where." A resort could offer parents every incentive to bring their children along, but if it's in the middle of a business park or nondescript suburb, then they may not have a particularly good experience.
Look for hotels that are close to things kids love to visit, like amusement parks, children's museums, water parks or the beach. If you aren't traveling to a major resort destination, try to find a hotel close to a city park or shopping mall, where kids can run around or hang out. Are the kids still bored? Some chains, like Loews Hotels and Resorts, offer a "family concierge" that can inform you of some of the family attractions in the area.
A room with a view is also a bonus. The excitement of a downtown cityscape or the beauty of a mountain lake can provide hours of entertainment for kids whose view from their own bedroom window is blocked by a wooden privacy fence.