Here, someone has hacked the original Nintendo Super Mario game to be completely in ASCII.
I've had a go at hacking ROMs over Christmas but I can't seem to get my head round it. Oh well.
Something equally as interesting, however, is the idea of glitch art. I have explored this a bit previously in my post about Cory Arcangel but never really got onto expanding it. I like the idea of using existing commercial appliances such as video game consoles and exploring creation of glitches.