I know somethings about both sets, and here is what I learned:
LCD is good for saving energy VERSUS plasmas.
LCD TVs last longer for their picture life.
Plasma screens will have a picture burnt in if shown too long in one place.
Plasmas can overheat very easily.
Plasmas ARE cheaper on the market.
Plasmas do have deeper black colors.
Plasmas are bigger in size.
LCD pictures are often more crisp.