According to my husband, there is no such thing as "too big" when it comes to TVs. Last year, I regaled him with stories of the Sharp 108-inch LCD TV, showcased at CES. Panasonic, one of the largest plasma manufacturers, is out to win the title this year with "the world largest consumer plasma flat TV," once again at CES, with their 150-inch model. The prototype was developed by Matsushita Electric Industrial Co. It has a size dimension of 138 x 79 inches which is big enough to stand in.
Fortunately (for me), it's not on the market yet and there's no word on pricing.