You could continue on with the CCIE. I think that there only 20,000+ of people who have this certification on earth. 17k CCIE routing & switching, while the other 3000+ in different fields.
That depends on what you want to do. If you want to be a Cisco Engineer then stick with the Cisco track. If you want to work with Microsoft products then you’ll need to look at the MCTS and MCITP certifications. If you want to work with Linux then you’ll want to look at certs for the flavor of Linux that you want to work with.