Se7en
I love the banter and relationship between Mills and Somerset the two characters work really well together and are really well casted. Se7en is so intense and shocking, there is not a single dull moment throughout.
Directing, Writing and Acting where incredible in this film. The end was really shocking and intense, I loved how John Doe's plan was complete with him becoming Envy and Mill's becoming Wrath.
Se7en is such a hyped and loved film and it fully lives up to it all. So far out of the David Fincher films I've seen he has not missed.