Just went and saw Art in the Streets at MOCA's Geffen in Little Tokyo. I say things are "the best ever" kinda a lot, but this warrants the title of best exhibit I've ever seen. It's a super comprehensive exhibit of the history of graffiti and street art with some of the biggest names like Keith Haring, Banksy, Shepard Fairey to name a few, with photography and film from the likes of Spike Jonze & Ed Templeton. It was so, so so amazing I'm pretty sure I could've camped out there for a few days and still not have digested all there was to offer.
Get your bum bum to see in person before August 8, I'm not sure there will be anything close to this for a long time.