I saw a couple that I'd been meaning to watch for years a couple of weeks ago when the mrs was away, I forgot to mention:
Exit Through The Giftshop - Ostensibly some sort of existentialist experimental shit by Banksy, but turned out to be a surprisingly conventional documentary about street art basically, and how it all kicked off. It's told through the premise of it being a documentary about some bloke who went round filming all the artists. I enjoyed it, and I learned a lot, but I came out of it thinking less of Banksy to be honest, they were far too ready to measure an artist's success through his bank account.
Four Lions - A Chris Morris masterpiece about 4 Muslims from Sheffield who decide to suicide bomb the London Marathon. I saw odd scenes of it when it was on the telly last year in the middle of the night and I was trying to feed my 3 week old lad, so didn't really take any of it in. It really is funny as fuck, and surprisingly moving in parts, and is the only thing I've ever seen that addresses the position some of these people are in with any degree of intelligence. That it can achieve that and be so ridiculous at the same time really is a triumph. And there's some beautiful shots of Sheffield in it an all, as if that were possible. I urge you all to see it, like, now.