Hi!
Last December we felt the same way, so we went to Cable Beach. If you search the boards and the trip reports, there are lots of positive comments about going there.
You can take a short walk to the bus stop and hop the bus to the Wyndham at Cable Beach for $1 per person. We brought lunch ordered from room service (subs and pbjs) and bottled soda/water we had brought on board. The beach at the Wyndham was BEAUTIFUL, and we used the pool as well. There is a casino if you're interested.
It was great because we left the ship when we wanted, and returned when we wanted. It was very cheap, and a relaxing, peaceful afternoon of the kids playing in the water and building sand castles. Minimal annoyance from people hawking cheap jewelry/hair braiding.
HTH!