The terms monster of the week episode and mythology episode started back in the late 90s with the X-files. To define the terms for those who didn’t watch X-files, the mythology episodes were more about a long arc and focused on the main characters’ stories. The monster of the week is more about that particular week’s mystery or adventure.
I tend to like the monster of the week episodes better than the long story building mythology arcs, especially when the latter involve the death of a favorite character. I’m wondering if anyone has taken the time to put together a database breaking down the episodes of popular long running shows into the two types. Any suggestions? If it helps, NCIS is the particular show I’m wondering about.