Panasonic's TH-152UX1 is a 4K plasma 3D UHDTV retailing for around $500,000.
It's 152 inch's! Consumes 3700W! Weights about 1,270 lbs!
http://www.panasonic.com/business/Plasma/3D/3D-Plasma-TH-152UX1.asp
http://en.wikipedia.org/wiki/4K_resolution
Not sure why they went with plasma and not projection technology for such a huge display.