I have some shit no name brand TV that I got a while back, I think when Oblivion came out for the 360, and I've never had any problems with it, either. I really want to get a new, bigger one, though.
I looked up Panasonic's Plasmas and Vizio's LCDs. Panasonic's were half the price, which shocked me. Best Buy's website has a Panasonic 42" LCD for $600. 50" Plasma for $750. Every TV on Vizio's website in that size was at least $1000.
If I had a choice between a 1080p TV versus a 720p TV that is larger for the same price, I would probably pick the 720p TV as the quality, at least in games, is almost negligible. For movies, I dunno 1080p is nice.
I don't know if I believe the cheaper TVs are just as good as the higher end ones. I had a cheaper brand of TV before my Samsung, and it didn't have very many features and comparing the picture quality there is a vast difference. The price difference between the two was about $200. I'm certainly much happier with the Samsung.