In my top10 all time favourite Wow, this movie is awesome. It will hunt you for a long time. Not only, that it is well made, violent and tragically, the acting is great (Kevin Spacey's performance is the cherry on the top) and the final is unexpected and you will never forget it
Spoilers: The idea that John Doe (Kevin Spacey) is one of the last two sinners and Milles (Brad Pitt) is the other one is great, because it adds up to the film massages: everyone is a sinner. Plus IT IS BELIVABLE that John killed (beheaded) Milles wife cause it is part of his sin, for which he dies. At the end, the bad guy won!
Tip: don't eat during the movie and keep the brightness at the TV high.