As a plot device a cliffhanger, in which a story ends with surprising revelations or seemingly impossible to resolve conflicts, is about as well worn as the MacGuffin and the deus ex machina, and just as with those familiar narrative devices it can be done well or badly: sometimes it leaves audiences desperate to know what happens next while other times they probably couldn't care less. While perhaps most common in formats such as television soap operas and serialisations in magazines, where viewers and readers are enticed into sticking with it for the next week's installment, the cliffhanger has cropped up plenty of times in movies over the years. With a few exceptions (the literal one at the end of the original The Italian Job being one amusing example) cliffhangers in movies usually signify that a sequel is on the way - and the job of the filmmaker is to make it as exciting and tantalising as possible. The more effectively a film can deliver its cliffhanger moment, the bigger the surrounding buzz in the intervening time before the next installment is released. Sometimes fans only have to wait a few months to find out what happened next (which in comparison to the weekly - or even daily - broadcasts for cliffhanger-heavy soaps is still a very long time), but for others, years can pass before the pay-off finally comes. It can be frustrating, but when it's done right the wait is worth it.
Honourable Mention - Blade Runner
It's fair to say that Blade Runner's initial lukewarm reception both from critics and the public was at least in part down to the dreadful Harrison Ford voice-over and unsatisfying happy ending - once these issues had been resolved for the director's cut a decade later opinion rapidly shifted and the film is considered by many a masterpiece. Blade Runner sees Deckard (Harrison Ford) hunting down a group of rogue Replicants led by Batty (Rutger Hauer), but transcends this seemingly run of the mill premise with its noirish production design and a moral ambiguity which makes the audience question the twisted ethics of the world in which it is located. With the happy ending removed, Blade Runner's wonderfully ambiguous cliffhanger ending has left people scratching their heads for literally decades. Is Deckard also a Replicant? It's a burning question that might finally get an answer with the upcoming release of Blade Runner 2 - although with Deckard set to appear in the latter half of the film it's perhaps fair to assume that the answer to that burning question is "no", given that if he was a Replicant he wouldn't be able to age as the actor has done.