JSON? RON? Protobuf? Cap'n'Proto? Anything with more types than "string" which is all CSV has, and with an unambiguous data encoding. Preferably also a way to transmit the schema, since all of these formats (including CSV) have a schema but don't necessarily include it in the output.
About half the problems with CSV are due to encoding ambiguities, the other half are due to schema mismatches.