17. Duane Barry (Season 2, Episode 5)
"They drilled my teeth. They drilled holes in my damn teeth!" - Duane Barry
In "Duane Barry," Mulder is called into a hostage negotiation with a man recently escaped from a psychiatric facility who believes that he has been (and will soon be again) abducted by aliens and subjected to terrible tests. As the plot progresses and Duane Barry becomes much more than he seems, the case gets dangerously personal for Agents Mulder and Scully. Unlike the majority of this list, "Duane Barry" is a mythology episode. Not quite so simple as a MOTW, "Duane Barry" can still be understood and enjoyed without extensive exposition beforehand. It has earned its place on this list because it is the first of a phenomenal three-parter ("Duane Barry"/"Ascension"/"One Breath"), all of which are so suspenseful that it is difficult
not to keep watching. At one point released on VHS tape in the 1990s, it left viewers in an era without DVDs or streaming videos devastated as they waited for the follow-up pair of episodes.