4. The X-Files
This show followed two FBI agents, Fox Mulder and Dana Scully as they investigated the X-files, unsolved cases that were tied very closely to the paranormal. Mulder is a believer in the existence of aliens while Scully is a skeptic. She was assigned to him to disprove his theories of aliens and the paranormal. The show ran from 1993 to 2002 and was a huge part of 90s culture.