Se7en
I actually find the ending to be one of the most intriguing and interesting endings in all of cinema history. Now, as far as I’m concerned (and as far as I could remember), the conditions that John Doe set said that Mills and Somerset had to only go with Doe to the open field at like 6 pm or whatever and just stay there and he’ll plead guilty. The condition never said anything about a box. In my opinion, I think there’s a big connection with the tale of Pandora’s box that the director put in the movie since Somerset never really had to open the box—curiosity just got to him. Of course, the open box led to problems (like Pandora’s box) that eventually caused Mills to lash out (with wrath, duh) and kill him.
I also found it really interesting that Mills believed that whatever Doe was going to reveal was going to be actually near both Mills and Doe (since he said he’ll be right next to him when he does whatever), but Somester was the one that ended up opening the surprise (even though the whole thing centered around Mills).
Either way, absolutely amazing film—one of the best ways I’ve seen a film lead up to its finale.