In terms of character study alone, The Hurt Locker is a singular work. Jeremy Renner's naturalistic lead performance, combined with Mark Boal's script, provides a very compelling portrait of an insatiable danger junkie. (not for nothing is the film's epigraph "War is a drug.") James is highly skilled at defusing bombs. He also really, really gets a thrill from it, a rush that civilian life can't provide him, which is what made the final shot of The Hurt Locker one of the more memorable closers in recent memory to me. Standing in contrast to James is Anthony Mackie's Sanborn (another terrific performance), who is, as Roger Ebert points out in his review, also a professional, but with an entirely different attitude than James. Without propagandizing, the film manages to make you consider the insanity of war, and the different ways in which those who must fight it choose to deal with it.
If all of this wasn't enough, Kathryn Bigelow and d.p. Barry Ackroyd do a phenomenal job visually. They have a great sense of spatial geography, and the action sequences are always easy to follow. In addition, the meticulous editing throughout serves to ratchet up the suspense. I don't care how much money was thrown at James Cameron's "game changer," I'll take the gritty realism his ex-wife has brought to bear with The Hurt Locker any day of the week.