4) The Monster-of-the-Week Format
Though the Monster-of-the-Week format was nothing new to television by that point (several mystery shows used this concept prior), The X-Files somewhat changed this up. The Monster-of-the-Week provided viewers who never regularly watched the show a chance to experience it without getting caught up in the storyline. However, whereas shows utilized this format as one-off stories never to really be referenced again, many of the X-Files Monster-of-the-Week episodes had important character interactions which strengthened the relationship between Mulder and Scully. It somewhat fed into the ongoing storyline without needing to fully know it. Several of the monsters and standalone episodes have been quite memorable as well. I think I'll always remember how scared I was when I watched the first season episode 'Tooms' for the first time with the fan-favourite Eugene Tooms, one of the only monsters to appear twice in the series. Another monster, Donald Pfaster, may have not been a monster at all, but a very real and dangerous person, playing on our fears of the unknown lurking in reality. Numerous episodes have gone on to be fan favourites as well, such as "Jose Chung's From Outer Space" or "Clyde Bruckman's Final Repose", an episode which earned Emmy Awards for Writing and Outstanding Guest Actor.