Karachi
Karachi should be separated from Sindh and made a separate province. The resources generated by Karachi are not used to develop Karachi, Instead they are used to develop rural Sindh. Basically the ruling party of Sindh has been PPP for years. But their vote bank is not in Karachi, they win their seats from rural Sindh. That is the reason they do not put effort in developing Karachi, Instead they took resources generated in Karachi and used it to develop rural Sindh. Disclaimer: This is my personal opinion.