Have you thought about the Bahamas? There's a hotel on Paradise Island call The Atlantis. They have an aquarium that's pretty much second to none. In some places, you walk through tunnels and the animals swim around you. The hotel is also on the beach. You can usually get package deals.
Highly recommended: a day trip to Rose Island. They'll collect you at the hotel in the morning, take you to the island, provide snorkeling gear, paddle boats, flotation vests, and much more, plus a yummy Bahamian lunch.
Val
