ISO has published more than 19500(appr) standards. But all standards are not popular or  adopted worldwide by the organizations as the following standards. Following ISO Standards are the most popular standards around the world:

1. ISO 9001(Quality Management System Standard)
2. ISO 14001(Environmental Management System Standard)
3. ISO 27001(Information Security Management System Standard)
4. ISO 22000(Food Safety Management System Standard)
5. ISO 13485(Medical Devices -Quality Management System)
6. ISO 50001(Energy Management System)
7. ISO 2000-1(IT Service Management System)
8. ISO 22301(Business Continuity Management System)
9. ISO 39001(Road Traffic Safety Management System )
10. ISO 28000(Supply Chain Security Management System)

Source: https://isotc.iso.org/livelink/livelink/fetch/-8853493/8853511/8853520/18808772/00._Overall_results_and_explanatory_note_on_2017_Survey_results.pdf?nodeid=19208898&vernum=-2