Season 3, episode 3. Original air date Oct. 6, 1995
Season 3, episode 1. Original air date Jan. 12, 1996
Season 5, episode 11. Original air date Feb. 15, 1998
In a series that was so definitive of the 90's, there are, of course, other episodes that practically oozed ninetiesness, but these 3 are some of my all time favorites!
If for some reason you never got into the series the first time around, or during any of the subsequent reruns, The X-Files is available streaming on Netflix instant. For me, and many others, this show was the show to watch in the 90's and it's not surprising at all that it's held up over the years.