I've been watching The X-Files recently, about halfway through season one. I remembered that the show had a tendency to leave large plot holes open for years and years, with many things not even resolved by the end of the ninth and final season. But one thing that I had forgotten is how frequently the episodes' individual plot lines are never finished by the end of the show.
I just watched one episode in which many murders were committed. The suspect of the first several was killed during the episode, and the person found responsible killed himself. But it was never made known who killed the original suspect.
It's annoying, in an occasionally cute sort of way.