Plasmas are bigger, and often rather brighter than their smaller LCD counterparts. The big drawback with plasma is what is known as 'burnout'. The display technology is basically a piece of glass covered in chemicals called 'phosphors'. With increasing use, these gradually burnout, and sometimes this means a detectable image has been burned on to the screen, which is then visible even when you turn the TV off, or is overlaid on the current image. As a result, plasma displays generally don't last as long as LCD ones do, and are fiendishly expensive to repair. BUT - they're very big and very bright!
