Gozo Island in Malta. In the summer months. Very beautiful. Very Friendly and has loads of old charm about it. Great little beaches and the water is so warm for swimming. Crystal clear waters. And it is one of the safest places in the World. You don't have to worry about your kids at all. When swimming you don't have to worry about your bags on the beach. People leave the front door open and guys leave their helmets on their motorbikes.
Price for eating out is very, very reasonable with great Italian pizza and Mediterranean dishes. Everyone falls in love with Gozo.
When my daughter was young, I took her to California, New York State, various national parks, Florida, New Orleans, Atlanta, the Netherlands, St Maarten ... When she was older, I funded a trip where she volunteered in the Cloud Forest in Costa Rica.
Disney, of course!
Or maybe some other amusement park. (Great Wolf Lodge is excellent, and there are several of those around the world)
If you don't like that idea, you can always go to a different country, camping, beach, or maybe a cruise.
Hope i helped!
Go to Hawaii and walk along the edge of volcanos! Kids will love that (hoping they don't jump in)