Here is an idea for a fun night out, You can take the kids to The Coastal Field and watch the Myrtle Beach Pelican's baseball team. I believe they are a Class A ballclub. Its a great new facility and general admission tickets are very reasonable. The hotdogs and popcorn are good too! Theres alot going on during the game to entertain you and they have "give aways" too. We were there last week and everyone at the stadium got a Free Roast Beef Sandwich at Arby's. They have a Labrador Retriever that runs the bases and delivers the baseballs to the umpires.
There are lots of miniature golf courses for the kids and yourself, and over at The Nascar Cafe you can get an all day pass so the kids can ride the gocarts all day for one fee. You can come and go all day long!
I hope you have a great trip! Val Dell