My opinion on "One Breath" has fluctuated over the years, but I seemed to have settled on a position of really liking it, but not thinking it was a truly great episode. Once again, my opinion on the episode has changed. "One Breath" is a wonderful and remarkable character-driven story, where the first two parts to the Scully abduction trilogy (which was interrupted by "3") were action-packed and intense, "One Breath" is somber and quiet for much of its duration, although there's one breathtakingly intense scene with Mr. X. The intensity here comes from a different place than it did with "Duane Barry" and "Ascension". It comes from genuine care for the characters.
My favorite shot in this episode, one which I've always liked even when I didn't enjoy the episode as a whole too much, is Mulder breaking down and crying after visiting Scully and returning home. It's one of the show's most emotional and tender moments, and just beautiful. While the mysticism is one of the reasons I'm not yet sure I personally love the episode, I found it worked really well in this context.
The episode is still a mythology episode and is hence still packed with intrigue. Mulder's meeting with Mr. X, the spectacular scene where he confronts CSM, the presence of the Lone Gunment (awww, Frohike brought Scully flowers!), and further development of Skinner's still fresh character make this something even fans of only the action-packed episodes will enjoy, even if its best moments are those between Mulder and Scully.
Oh, and Duchovny's just brilliant here.
9.5/10