Aruba was also very beautiful. My second favorite island after Nassau, Bahamas. Much more developed than the other islands.
Curacao was gorgeous and very colorful. Beautiful beach. Could've stayed there all week long.
Nothing much in Grand Turk apart from the cruise port. You could probably walk the whole island in the time you are there. Did a tour and saw a lighthouse with a nice view of the ocean. The cruise port was nice, with a nice beach and pool/party area.
Got a great zip-lining deal in DR. Took a taxi to the site for $15, and paid $50 to zip line. Carnival offered that excursion for $109. Was pretty good for our first time, but next time I want something a little more adventurous like mountainous rain forests or rivers or something (this was a wooded area off the highway).
Some of our group did a tour in La Romana and got ripped off. They took a trolley that was run by Carnival and paid $19 for a tour and beach trip (they paid using their sail and sign card). Turned out to be a 20 minute tour back to the ship! They got reimbursed 50% after complaining en masse.