Two things that come to mind are ones where it seemed that way. In the movie enemy mine about or maybe over an hour into it it seems like the protaganist dies and it was going to end on one heck of a gloomy note. Especially seeing it in theaters before cell phones when you did not know the exact time. Then also in the supernatural series at one point which I think was the season 1 finale it looks like everyone died. I was super hyped because I was thinking the show would follow a different group of hunters every season that bought it fighting the supernatural. Don't get me wrong the series was still good but it could have been so epic.