Hi Stacedawg, welcome to CruiseReviews! Congratulations on your up-coming cruise, just be warned cruising is addictive
MCPayne and Peterl have given you some great tips. It really depends on what you enjoy doing. If you like snorkeling, Cozumel and Grand Cayman will be your better options. Jamaica, definitely Dunn's River Falls. Grand Cayman's Stingray City is the notable tour. If you enjoy snorkeling, Abanks would be a great place to check out. If you just want to go to the beach, 7 mile is beautiful. Labadee is their private island, so beach day if you're not into Zip-lines. Cozumel, Chankanaab Park is better for snorkeling than Paradise, but both places offer good beaches and ammenities. Paradise does not charge to get in, but does not have the zoo area, snorkeling area, shops, dolphins that Chankanaab does. We rented a scooter the last time we were there and went around the island, it was a ball. We stopped at every beach location we could find. Nachi CoCom was really pretty, it is an all-inclusive and they only allow 100 people in, you have to do advanced reservations. We're going to try the Money Bar in December. Cozumel is not hard to get around, taxis are all over the place.
If you let us know what you enjoy, we'll be able to offer some suggestions directed toward your interests.
Have a marvelous time!