WebInvoke(BodyStyle=WebMessageBodyStyle.Bare, ResponseFormat=WebMessageFormat.Json)

1. http://blog.clauskonrad.net/2010/11/how-to-expose-json-endpoint-from-wcf.html

[OperationContract]
        [WebInvoke(BodyStyle=WebMessageBodyStyle.Bare, ResponseFormat=WebMessageFormat.Json)]
        Employee[] GetAll_POST();

2. http://stackoverflow.com/questions/9235743/return-json-array-with-name-from-wcf-with-service

The easy way is change BodyStyle = WebMessageBodyStyle.Bare to BodyStyle = WebMessageBodyStyle.Wrapped.

The Wrapped enum member does it for you.