I've been fortunate enough to travel to a lot of beaches in my lifetime. From Maui to the Baltic Sea, from Isla Mujeres to Isla Roatan, and many in between.
One of my favorite family beaches, though, is simply Pensacola Beach, Florida. It isn't as epic as some others, but it's a comfortable and affordable destination for an easy family trip.
There are plenty of quality accommodations, numerous restaurants, and parking is never a problem. Add the beautiful white sand and calm waters, and you have a great place for you and your kids.
Less than 30 minutes from the beach, you can also catch a minor league baseball game at one of the most beautiful baseball stadiums around. Or visit the excellent Naval Aviation museum that's much better than you can even imagine.
All in all, if you ever have the opportunity to visit Pensacola, Florida, I highly recommend it.