We went to Sunset Beach Resort, Spa & Waterpark in Jamaica and spent day there and then checked out Margaritaville. This was in 2005 and our kids were younger then (5 & 12, nephew 8, niece 3) but we all had a good time. I know that Sunset has added some things since we were there. If I remember correctly we arranged a taxi for the whole day when we got to Jamaica.
We did the Hell/Turtle Farm Tour with Captain Marvin's Tours in Grand Cayman. They were great.