I have Waltz With Bashir, but I have yet to watch it.
In terms of non-plot driven movies, you still need to have something driving the movie. For instance, characters. There Will Be Blood has very little plot, but extremely engaging characters, and is one of my favorite movies. The Hurt Locker is in no way character driven, I can't remember a single one of the characters.
I'd also argue that what you described in the Hurt Locker, while plot development, is not necessarily plot. Saying "This is a movie about the members of a military unit's relationships to one another, and how it progresses over one tour of duty." sounds like a plot, but try to write that, and you'll soon feel like there's something lacking: Drive. There's only one thing motivating the characters, and that's survival. But in good plots, the main character acts on upon others, which leads to the next plot point. You can't just have a series of things happen to the main character.
I'm making it sound like I disliked the movie much more than I did. It would definitely be in my Top 10 for this year, and I'd definitely want The Hurt Locker to beat out Avatar in any award ceremony's. But in truth it's a movie I enjoyed the first time I watched it, and I will never watch it again.