I watched Restrepo last weekend. Definitely a very strong film, although it's got the problem that all films/books have that depict something that has long, boring stretches - the depiction of these becomes somewhat boring itself. Which makes it all the more effective when things are happening, though.
Tim Hetherington also did an experimental short last year that makes for difficult watching, especially if you consider his recent death. It's contemplative and definitely not good viewing for people with little patience, but well worth checking out IMO.