I don't know about you but I don't think that "G-Unit wuz herrre" spray painted on a wall is a valid form of self expression. I mean, it's like a dog pissing on a tree to mark his territory. I would like to think that, as humans, we are a tad bit more evolved than that.
But that's not the point.
Despite my distain for graffiti, I really like Banksy. He's a British street artist and he has some really amazing work.
Here are a few of my favorites [click for full effect]: