As many others have stated we like the larger Oasis Class ships with so many things for everybody. One thing that has not been mentioned ( at least I didn"t see) is booking a cruise that has at least one stop at
RCCL's Island CoCo Cay! If they are into waterslides then this would be their trip of a lifetime. Caution they are an upcharge, but if you watch them frequently you can find some major discounts for full day pass! Usually lists for around $109 / Person. We have booked for $50 multiple times. They also have a wave pool they might like that is covered by the waterpark pass. They have zip lines that can be expensive also but you can sometimes find a bundle package with the waterpark. I will try to post a link but if it doesn't work search for Perfect Day CoCo Cay full walkthrough. ( Warning it is 45 mins. but informative. Stay Safe