From personal experience I can highly recommend Daydream Island.  It is such a cute, lovely resort located in the beautiful Whitsundays.  It is also very easy to get to.  There are two airports you can fly into, the Great Barrier Reef airport on Hamilton Island or the Whitsunday Coast airport on the mainland at Proserpine.  Flying into Hamilton Island is more convenient as you can then get a boat transfer to Daydream Island which takes approximately 30 minutes.  If you fly into Proserpine, you have to get a coach connection from the airport to Abel Point Marina at Airlie Beach which takes 30 minutes, then connect with a ferry transfer to Daydream Island, allowing another 30 minutes.

I think it is perfect for families!  Kids absolutely love all the activiites and they never get bored.  There is a daily activities program and every Monday, Wednesday and Friday they feature the latest released movies in a unique open air cinema.  For good value food and a great atmosphere I would suggest the Fish Bowl Tavern.  Serves food such as steak sandwiches, burgers and chips and nachos.  A day trip to the Outer Barrier Reef is also something you should budget for.  You will be amazed by its beauty!