Our priorities would be with excellent food and outstanding service. Then, entertainment. We would like to be on a cruise that is not catered to young children.
I would suggest either Celebrity or HAL, with Celebrity being my first choice. Both ships limit the amount of children, in fact every once in a while Celebrity will promote an "Adult" only cruise, where no one under the age of 18 is allowed on that particular sailing.
I loved the atmosphere on Celebrity we have cruised on both Century and Millenium. The food was great and could not ask for better service, both in the dining room and in the stateroom.
Whichever line you choose, you will have a great time, there is nothing like a cruise for a vacation.