And at the other end of the scale, we have... Cardiff Central Railway Station.
Seriously though, I love the pixellated ninja. That looked like it took a lot of trouble, actually.
One of my personal guilty pleasures is graffiti in old videogames. From the great (Space Invaders aliens and spiders from the C64 version of "Renegade" - hell, even the high-score table was graffiti) to the awesome ("Banana" and "Sausage" in "Two Crude Dudes". I'm not even kidding.)
A pet peeve of mine is when characters write stuff on walls in their own blood in horror-themed videogames (which happens surprisingly often) but the writing is WAY too large. There's one wall in "System Shock" where a four or five metre space is literally covered by the word "RESIST" in giant capital letters, all written in blood. I mean, holy hell, what did the guy do? Rip open his own chest with his hands, then splatter the red stuff on the wall with a ladle? PAINT, dude! It's a lot more practical, and the only way you die afterwards is if you inhale too much of it by accident!