The general impression I've gotten from talking to a wide range of "experts" in the field is:
If you're mainly going to watch TV, go for plasma, it's more forgiving on defects, and will give you a more comfortable experience.
If you want to connect your computer and do websurfing, go LCD, plasma is not accurate enough for a perfect image pixel per pixel.
The cheap TVs (discounted or not) use several years old panel technology (I've seen TVs using 5 years old panel technology, even though being a "new" model...) ... Don't expect getting something good just because the TV you consider buying had a double pricetag last year. A midrange TV generally has last years (sometimes even 2 year old) panels, which means that the TV you buy now at a great discount has at least 2 years old technology... So if you want a quality TV, buy one that was top of the line last year, it'll cost you more, but it'll be a recent panel... (It's not *always* true, so better research a bit before deciding). Ofcourse, buying a TV with state of the art panel is the "best" option, but that comes with a huge pricetag. 