Most people associate graffiti to some kind of simply scratched tags, that you can find on pretty much every street corner anywhere in the world. But there's so much more to graffiti, also some things that are really taking things to a whole new level. In some instances, it's pretty much impossible to imagine such a piece being made with spraycans and flatcaps.
Take, for instance, a look at the work of the German artist Tasso, who does some amazing illusions within graffiti.
Or what about Maclaim? Another artist with a completely unique style of photorealistic graffiti. It's not just "scribbling on a wall", but I think it's safe to say that this is pure art. Made by people who definitely think outside the box.