Would recommend Royal Carrribean for children's activities..they have very well supervised children's clubs and activities. Be careful about the age bands for kid's clubs. We are going on Independence with 6 year old grandson next year. RCI age range is 3-5 and 6-8 which is fine, but you will find others (P&O included, I think) have broader range from 3-6 and 7-10 for example. Our 6 year old would certainly not be happy in with the 3-6age range - too babyish!! Food, service, quality and decor on RCI ships are superb and the range of activities and shows brilliant - especially the ice show
Whichever you choose - ENJOY!
P&O Ventura is ideal for young families. They have an excellent supervised childrens areas in four age groups, which also includes evenings so you can have time on your own if you wish. There are non stop connecting flights to Barbados from most UK regional airports. If you are in Poulton Lancs, there are flights from Manchester for every cruise and choice of Fri or Sat departures. Presume you mean Jan 2009? See http://www.pocruises.com/ Also have a look at this page which explains childrens activities http://www.pocruises.com/Help/families.axd.
The words 5* cruise and child-friendly cruise do not really go together I'm afraid. Yes, certainly RCI is the best by far for children, but you will not get the 5* treatment that I suspect you are looking for. P&O are very British and do not have the glitz and glamour of the US liners. I would suggest the new Celebrity ships - Solstice and Equinox - generally agreed to be the most stunning innovative ships afloat, and they do have kids clubs, but because of the usallly smaller number of children on board they get more attention.