Many families these days are in love with Caribbean all inclusive beach resorts, with kids' programs and myriad activities for all ages. For summer vacations, the good news is that prices drop dramatically from May to mid-December.
Head to Caribbean Beach Resorts: lots of all inclusives, and non-AI choices as well.
For something different than a beach resort, consider a deluxe camping resort on St. John in the US Virgin Islands: white sand beach, comfy tent-cottages.
Of course there is that little matter of hurricane season... You can follow some strategies to reduce risk; also, many major properties offer bad-weather guarantees. Read more about hurricane risks.
Mexico, meanwhile, has many all inclusives, and also has a long Caribbean coast; summer prices don't fall as sharply as in the Caribbean, but some Mexican AI's start at a good price point.
Over on the west coast, the Riviera Nayarit area, north of Puerto Vallarta, has a cluster of new all inclusive resorts and is growing popular.
Head to Mexico All Inclusive Resorts: in Cancun, the Riviera Maya (which has much to explore outside the resorts), Los Cabos, Riviera Nayarit, and more.
And some Caribbean ideas in Central America: