Customizing computer cases is very popular these days and several websites are dedicated to the endeavor. A Robot-themed enclosure is a perfect match for a blazing motherboard and heatsink-engulfed video cards.
Futurama's Bender has also been violated with PC components (Mini-ITX in this case) in this fantastic case mod by Jan Erik Vangen.
Eric Burke tosses his cap into the mod ring with this super-inexpensive, antenna-topped Android case.
I'll finish off the list with an incredibly ambitious and over-the-top Wall-E case mod by 'this Russian guy'. The amount of work this must have been is amazing, not to mention the cost of the raw material. I wonder what it weighs?