Mandalay Bay, but it's located pretty far to one end of the strip, so not an ideal location.
There are a few resorts that are now 100% smoke free, if that is important to you as a family. Parl MGM is one, although their pool isn't amazing.
I would recommend trying to stay center strip. The summer heat makes walking almost unbearable during the day. Minimize that as much as you can by picking a center strip hotel. We like the Planet Hollywood. The pool area is fun without being rowdy and they have stuff like ping pong tables under cover poolside.