Hontou ni Atta Kowai Hanashi [ほんとにあった怖い話] Goro is a ghost-fighting super hero? [Rating: 10/10] Not really a Drama, I'd say, but this series is definately great. Goro is the head of the "�ق�|�N���u" which (much to my amusement) spends half of it's time taking pot shots at "Goro-sensei."
This show is probably not based on things REALLY happened but at least they're never boring. The Japanese flare for ghost stories is really brought about in this.
I'd say the scariest part is definately the ghost pictures.