I was always a fan of the G4 cube, and even considered picking one up from eBay so that I could upgrade the specs to something more respectable. Alternatively you could take a different approach to bring that classic design back into your house.
Image via Nowhere Else
Cram a Mac Mini, Airport Extreme and external hard drive into it. Clever, although all the different colors in there ruin the overall look for me.
Read more about the project here (if you read French).