DVD Extras

"The Story" audio commentary on Se7en
One of four different chat tracks on the Se7en DVD, this one features Richard Dyer, author of BFI Modern Classics: Se7en, analysing "the cop-thriller film genre", while director David Fincher, writer Andrew Kevin Walker, editor Richard Francis-Bruce, and New Line President of Production Michael De Luca "discuss the script and project history".
It's not a commentary in the sense you might expect -- these people aren't sat round together watching the film; rather, they're more like interviews, edited together thematically or what have you, usually with minimal or no relation to what's on screen. Arguably it's allowed to be more interesting this way.
What it could do with, however, is subtitles saying who's speaking, which I've seen put to good use on other commentaries that have dozens of people. Yes, there's 'only' five people here, but they've all been recorded separately and some sound quite similar, so it's easy to forget who's who.