That would be emo.

I don't really have a dark side, so I'll just say that I say dark things when they suit me.

For example:
While going home my group was supposed to go by a supposivly haunted field. A bunch of campers died or some story like that. They forgot.
On the way home I mentioned they forgot to go by, they said too bad, we'd go next time, to which I replied: "But I...wanted to hear the children scream...".
Yeah, everybody laughed.

I also enjoy the writings of Thomas Harris.