The Sixth Sense, if you can go into it blind. I'm usually pretty good at figuring out a movie's plot twist, but this one caught me completely by surprise. Then when you watch it again you pick up on all the dropped hints.
It was my first movie by shamalama and i didn't see the twist cuz i didn't expect a twist. Every movie he did after i knew one was coming and they it was easy to catch the signs...badump pssh
I figured out the twist within like the first 5 minutes of my first watch (nobody spoiled it for me, but I knew that there would be a twist and was looking for one) and it made the movie pretty boring imo