What is the greatest cliffhanger/ambiguous ending in movie history?

I watched John Carpenter’s The Thing today, spending about 5 minutes scratching my head at the ending and it got me thinking. What’s the greatest Cliffhanger or Ambiguous ending in cinema history? It’s a genius ending and I’m just curious if there’s more great endings like it that are ambiguous or a cliffhanger. Any Suggestions? via /r/movies https://ift.tt/Fp5Whty