11.) “Dallas,” “Conundrum” (1991)

J.R. Ewing (Larry Hagman) contemplates suicide in the final episode of this famous soap opera and is greeted by a spirit named Adam (Joel Grey), who takes him to see what the world would be like if he did not exist, a la “It’s a Wonderful Life.”

It turns out that Adam is a satanic demon — not an angelic figure — who wants to see J.R. suffer. That said, the series ends with the sound of a gunshot as brother Bobby (Patrick Duffy) frantically runs into the room. Viewers did not know if J.R. lived or died; fans were left with a new mystery and no closure.