Are we talking "dark" in terms of what a goth teenager writes in their diary and calls poetry? In my eyes a good dark story has to have light to be juxtaposed against. A long string of dark events would not tug your emotions as much as a few dark moments mixed in with brighter, more joyous moments.
Or maybe dark as in hard to see shit?
In that case should probably switch to FPSs and play quake