Hey Kevin,
Plasma blows away LCD as far as brightness, contrast and black levels are concerned. The biggest drawback, and it is a big one, they are good for a max of 3 to 5 years. The TV will slowly lose brightness over time until it is totally unwatchable and there is nothing you can do to fix it. With an LCD you can just replace the bulb that backlights it. Of course that bulb costs between $250 and $400 to replace. If you really, really, really want to hang it on the wall then go with LCD. If you don't mind a floor model then DLP is what you want, it has almost no negatives. Plasma is brighter, but only for awhile. Blacks are better on DLP. You can get a bigger screen for less money. They are fairly skinny now and weigh next to nothing. The bulbs are replacable. If you go DLP get SAMSUNG. They are the leaders in this technology. Everyone else is on their first or second generation chip, SAMSUNG is on their sixth. They have fixed all known problems with DLP, like the rainbow effect that salesman still talk about to try and get you to buy plasma. Let me know if you have any other HD questions.