6. Prisoners
This'll require explaining, because at first glance you'd probably think that Prisoners' ending isn't ambiguous at all Hugh Jackman's hysterically-named Keller Dover gets imprisoned in a hole in the ground, and Jake Gyllenhaal's Detective Loki finds him courtesy of the safety whistle Dover's daughter left down there during her own incarceration. The only thing we lack is a proper ending there's no ambiguity, but what's happen is so obvious implied that you might almost call it super-liminal ('HEY YOU, JOIN THE NAVY!'). However, screenwriter Aaron Guziowski is determined to make us think he made the film's ending totally ambiguous, judging by an interview he gave to Buzzfeed. Have a read of his choice of ending below.
"They move the car. They see he's down there. You know he's going to be taken out of the hole. I like it much better being ambiguous. Even though you assume that's what's probably going to happen, I like that there's a small chance that he's not going to get him out of there for whatever reason."
Guziowski believes the audience could think Loki is so unbalanced at that moment that he would possibly leave Dover down there, because of his antipathy toward the guy. Yet honestly, I didn't get that at all, and neither did anyone in the screening with me. This wasn't like Inception's will-the-top-stop-spinning ending which drew audible gasps when it cut to black it was very cut-and-dry, and we all knew from his face that Loki knew where Dover was, and that he'd fish him out to conclude the case that came so close to utterly destroying him. Frankly, I've honestly not come across a single person who bought into Guziowski's attempt at ambiguity, and I'm not sure I ever will. It just seems like the writer is trying to make a mysterious mountain out of a mundane molehill. And now, I'll stop with the alliteration.