When did The X Files "Jumped the Shark"?

The other day I accidentally jumped into a forum conversation where the question above was raised... After looking for this expression in the dictionary (for no-native English speakers like me, here is some info about where this expression originally comes from) I posted a coment argueing why I defently think it NEVER JUMPED THE SHARK:

I do have to admit that there were some shitty episodes (one of the comments pointed "First Person Shooter" as the episode where the show jumped the shark and I have to admit this was one of these shitty episodes) and it is also true that, at certain points, the original magic of the show seemed to be fading away (specially after David Duchovny left the show in season 8)... But the thing is that just when it was least expected, a new great episode would air containing all the elements that made this show so memorable: intelligent dialogues, philosophy questions beeing argued, a beautiful photography... And of course, the way in which these 2 characters could express so much with only a gesture, one look or one hugh... And I think here lies the real key of the sucess of this show: Mulder and Scully' characters were just so complete, because even though the audience was never aware of their feelings (they didn't use to talk about themselves and we'd rarely see any aspects of their personal lifes) we all knew what they were longing for, what were their deepest fears and, of course, how bad they were dying for each other... And the credit goes for the wirters, but also for Gillian Andeson and David Duchovny's great interpretation and the very well-known “chemistry” between them... DON'T YOU THINK? ;)