List your top five "Dark Ending" or "F'd Up Ending" (however you phrase it, like a wicked twist or such) movies of all time. Doesn't have to be in order, just your five fav's. Then if you want say your #1. Explain if you want why you picked what you did (don't have to of course).
Me:
The Road
Surveillance
Memento
Inception
Se7en
#1: The Road (dark ending, not f'd up - well, you could say it was pretty f'd up too)
If you are going to talk about the end of a movie, put up something like **SPOILER ALERT** or similar, so people can read this and then go enjoy the movies that are recommended (if they so wish).