Sure you can if you want tp pay big bucks for a converter that will translate VGA signals to NTSC signals. You pay anywhere from 50 bucks to thousands of dollars. The big TV studios have special cards that cost many thousands. If you use a 50 dollar converter then the TV looks terrible, ragged and not all pixels are filled. A 200 dollar card will do better, but if you paid several thousand for a Plasma screen, why would you settle for a so so picture?
See: http://www.ramelectronics.net/html/PC-TV_video.html#hd for some ideas.
Will a plasma Tv work as a PC Gaming monitor?? Im thinking about buying one in October.