Miami or anywhere on the Florida Gulf Coast is absolutely beautiful, especially between May and July!
If you're looking for a beach or a nice resort there are literally 100s of places around the world. There is no difference between place A and place B. I love the beach but I hate resorts. They get boring after 3 days and you can only read so many book. But if that's what you want then there really isn't any difference between the places. Go to Mexico. That seems to be a popular place.
You can go to Costa Rica, Nicaragua, Belize or Panama. These are some of the breathtakingly beautiful places to see in Central America. These places have lovely beaches, secluded beach towns and strange hidden beaches with white, pink, black and even green sand which is a rare sight to see.
We loved Bermuda and Cape Cod in the summer.