I think what stands out most for me when watching Se7en is the subtlety. There is no attempt to glamourise the violence, nor indeed horrify the watcher through the brutality of the deaths. What you see is what you get, and that is what makes this film so thrilling and shocking.
The power of the story is that it is not contrived. There are far better "cop films" out there, which play to the usual stereotypes and give you exactly what you expect - the "I'm too old for this shit" senior cop alongside the young rookie who shoots first asks questions later. What you get with Pitt and Freeman are two incredibly believable performances by two of the best actors in the business. Their relationship and how they go about their investigations just work so well together without falling into the same trap of every other cop movie.
What brings the film from being a good movie into being a truly great movie is the presence of the best actor of this generation as the villain of the piece. Kevin Spacey is just sublime. For the last twenty minutes of this movie watching Spacey and Pitt bounce of each other is just movie gold - even despite the fact that I knew what was coming next it is still heaping on the suspense while doing very little but talking.
To me what brings this movie into my Top 10 is perhaps one of the most mesmerising endings in a movie. Ever. I am so pleased that they chose to go with the version that they did - the alternatives would have brought this movie right back down to a stereotypical cop film - and the sheer ingenuity of it all is just brilliant.
This is an awesome movie, with some outstanding actors and a truly great storyline.