After yesterday’s best cliffhanger, comes worst cliffhanger.
This is much more difficult. I suppose ‘worst’ might be when the outcome is pretty obvious as to what comes next. VOY’s season 5 finale Equinox featured an apparent moment of peril for Captain Janeway, but she was never likely to die. The destruction of a ship in SG1’s season 9 finale never actually set up the possibility of main characters dying.
I think the worst cliffhanger I can think of recently would be any one of a number from Supernatural. They strike me as being pretty contrived a lot of the time, especially when you know nothing will permanently happen to the main cast.