It would be a toss-up between Belize and Cozumel. At Belize we were advised not to go very far and the "unrest" unnerved us! Cozumel - twice - so HOT! HOT! (in April) and unless you go to one of their pretty beach areas, not much to do except shop and we thought they were a little high $. Some people were killed on a scooter there by a local vehicle - they were from the ship next to ours.
Loved Bahamas - beautiful water and scenery!