Hi Champdds,
The solarium area on the Rhapsody was very well policed to keep children out of the area. It was very quiet and peaceful while the main pool area was very active, noisy, and exciting with youngsters enjoying themselves. Trying not to repeat what other posters have said, the best cruises for adults and the older crowd are:
--Value season
--Longer itneraries
--More exotic itineraries
--More expensive cruise lines
--Smaller ships
Some of the specific lines I'd recommend (but not limited to) are Seabourn, Silversea, Crystal, Radisson, Princess (exotics), Holland America, and Celebrity for the more mature crowd.
I was on a 10 night Princess Panama Canal voyage at 28 years old, about 5-6 younger people on-board. It was a wonderful cruise!
You can call the cruise line and ask how many children they have booked and ask if they even expect to be running a childrens program. (They won't run the children's program if they don't have enough children on-board.)
--Cruise_fly