BasicHttpBinding exposes a SOAP 1.1 wsdl which is probably the most interoperable between JAVA and .NET. If your calls are local then you won't go out to the network.
EDIT
WsHttpBinding supports SOAP 1.2 which is a larger, more complex specification and therefore more open to interpretation by different vendors. So while it may work fine, it will generally be less interoperable.
Specifically there may be differences in the way security is handled on either side (see here for a good explanation).