NCL does a good job with their kids program too. So maybe its safe to say that all the major lines have good kids programs? I agree with Dave on the Freedom class RCCL ships having more kid friendly activities (adventure ocean) but other than that the lines are all pretty good at providing fun for the little ones. The cruise lines are not dumb. They know if the kiddos enjoy a cruise, that allows mom and dad to cruise more often than if the kids had to be left at home because "there is nothing to do"
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007