Most of the suggestions just seem to be for a cheap and powerful graphic display. There are plenty out there already, e.g. the many full colour mobile phone screens that are well documented.
To be different and better than the rest it will need something special. How about layered displays for a nice parallax effect? Or maybe Seeedstudio could be the first company to bring eInk displays to hobbyists. eInk would be awesome for so many projects, since it requires no power to maintain an image and is readable in daylight.