We did the "Snorkel & Stingray Adventure" excursion, and had a lot of fun with both sections. They were actually at different beaches. I would definitely have to say you have got to go to Gibbs Cay to see the Stingrays, and interact with them near the beach.
Our final port was Half Moon Cay. I have been here and Coco Cay, and Half Moon is my favorite by far. DF and I rented a Private Cabana, and with some winnings from Gambling, I upgraded us to a Butler package on the ship. The water was cold, but crystal clear. We had massages in the cabana. One of the most restful and relaxing days I've had in a very long time.
I would definitely get a Cabana again if I had 4 people, for 2, it's a little pricey; but it was my DF's first cruise, and I wanted to make it special. It would actually handle up to 6 comfortably, as there are 2 chaise lounges as well as a table with 4 chairs in the main part of the room. (It's basically a deck, with a little 3 wall room on the end). There is both AC and a Fan in the room, as well as a fridge. There's also a fan near the chaise lounges that can be used as a misting fan if it was really hot.
The butler package gave us a good meal from the Pinnacle Grill, 5oz Fillet & 5 Shrimp Skewers (we got 2 of each), however, they were a little on the cold side by the time we got them. We also had Brut Champagne, which since neither of us like it, we gave to some friends to share with our table mates as we were eating at the Pinnacle that night. I would not have normally paid for the butler package, but I really liked the idea of spoiling my DF that day, and as I had won a nice chunk in the casino (almost $500), I paid for it with the money from that, so I figured I was still ahead, and it was "free".
We were joined by 2 of our table mates towards the end of lunch. We got our butler to get some drinks for them and we spent the last few hours sharing our humble abode.