Labadee was surprisingly good. Great Beach stop. We didn't do any excursions...just got off and went to the beach for a few hours. Snorkeling...go to Adrenaline Beach...best place but its still so-so......but free snorkeling (with your own gear). They setup a Buffet at Lunch at several locations.
Jamaica - Look, been there before (week for Honeymoon at an all-inclusive). Jamaica is Jamaica. People hound you to sell stuff, is what it is. Not much to do outside of the Port area in Falmouth. Exit the Port area at your own desire...nothing to go do anyway and you will be haggled every 5 seconds. Would HIGHLY Recommend doing an excursion (ship or from good company) here as its not a good go out on your own place. We did Dunn River Falls (must if you have never been) and Horseback riding. We enjoyed it. Dunn River Falls was a cool experience. Bring watershoes and a waterproof camera.
Grand Cayman - We are divers so we went diving. Great dive shops all over the island, don't feel the need to use the Cruise Dive group. Diving in Cayman is world famous. Cayman is know for Duty Free shopping. Lots of shopping in the port and several good bars/Island Restaurants to go park at within walking distance and have a good time. If not, I hear 7 mile beach or the Stingray City excursion were good (from other cruisers we were with). You can wing it and do your own thing (non boat excursion) in Grand Cayman. Felt very safe/crime free in Grand Cayman.
Cozumel - LOVED COZUMEL. Diving was AMAZING. Used a small local dive shop, Deep Blue Cozumel and the Dive Master was AWESOME. Nothing flashy about their shop or their dive boat....but the Dive Master was great and our dive group was a group of 5....counting the Dive Master. Got off the dive boat right in downtown Cozumel near lots of bars and shops. 1 dollar beers everywhere... Senior Frogs and Carlo's and Charlies had great food and drinks before heading back to Port Area (less than 10 minute Cab 7 buck flat rate). AMAZING Fajitas is Carlos and Charlies. I felt VERY safe in Cozumel. Don't think about crime ridden north Mexico when you think Cozumel. Safest I ever felt walking around or in a cab in all of the Caribbean was Cozumel. and I have been all over the Caribbean. I just say this because so many people were worried about Mexico...Cozumel LIVES off of Tourism and you have nothing to worry about there. DONT STAY IN THE PORT, TAKE A CAB DOWNTOWN. You can wing it and do your own thing (non boat excursion) in Cozumel.