I'd suggest any one of the "Voyager" class ships of RCCL, they are great for cruising with kids/families. Lots to do onboard, parades, all kinds of shows and a not to miss ice show, rock climbing, skating, etc. They have one in all areas of the Caribbean too.
I too agree with Donna. My 9 year old daughter has been on 12 cruises and last year's voyage on the Adventure of the Seas was her best yet. The roster of youth activities is very full, which she loves. She also loved the ice show, mini golf, rock climbing wall, etc.
Keep me posted on what you decide.
Luisa Frey Gaynor
Family Cruise Editor