Dramas/Movies involving Serial Killers (RANKED)

Following are the dramas/movies that heavily incorporate serial killers into their plotlines (so no Taxi Driver since it is kind of an anthology). By serial killers, I don't mean mercenaries, assassins, or professional hitmen. 

The ranking isn't based on the overall quality of the movie/drama (see ratings for that matter)  but rather on how it handles the subject matter being discussed.

For those that I haven't watched, I'll remove them if upon watching I decide that they're not up to the standard explained above.

If you're aware of any drama or movie that involves such storyline, you can either comment on this list or even message me privately. I'll respond as soon as I can.