Quick TV primer (I am not claiming to be an expert, just what I've noticed)
Plasma - generally 40" is the smallest. Highest energy consumption. Best blacks, best motion, best viewing angles.
LCD - all sizes, medium energy consumption, cheaper than plasma, terrible viewing angle maximums, poor blacks, motion (as in sports) is terrible, though the 120hz ones offer advantages over 60hz
LED - newest rage. Uses LED as backlight instead of flourescent. Cheapest on energy. Similar limits as CD, but aledgedly blacks are better, contrast is better, and motion is better, but still not as good as Plasma. Most expensive currently.
FWIW - I just bought a 42" Panasonic Plasma at Best Buy for $899. It's a nice set. You can watch it up close or far away. I could have bought something less expensive, a 52" LCD at $599, but the overall viewing experience and quality is superior, at least as far as I am concerned.
At home, I have a 52" and a 42" plasma. Most of the people I "hang" with have LCDs. I don't watch tv at their houses much - seems to bother my eyes for some reason.
Hope this helps instead of confuses.