Who is the current today's Islam leader?

Muslims follow the Quran and the Sunnah. Quran is the sacred book that God has sent to Earth and Sunnah is the ways of Prophet Muhammad, peace be upon him. If the followers of Islam are seeking for the answers (ie. what to do if such and such happened) that are not mentioned during the time of Prophet, peace be upon him... there are Islamic scholars who have the high possibility answers according to the Quran, most likely and that they thinks is correct.