Dimly lit room: Plasma, LCD, or DLP

A 42" class plasma will consume about the same amount of electricity for 3 to 4 hours of daily use as a modern full size refrigerator consumes in 24 hours. The WSJ says to add $200/year to your electric bill for the purchase of each large plasma (this obviously varies by location and usage). LCDs are more efficient, but still relatively high energy users. Roughly a third less than a plasma. Old-school CRTs are by far the more energy efficient.

LCD/Plasma power usage:
http://reviews.cnet.com/4520-6475_7-6400401-3.html

Plasma are best overall. As Chad says above - LCD's do not do blacks well at all. IMHO there is NO comparison (I own both)

Plasam burn in issue is not a factor as it used to be, and Green.....well thats more a political choice but for video use (and I assume thats what its really about) Plasam is still at this point the better option for total picture wuality. If you arw a green follower, or worried about Plasama reflective gloss screen then LCS is best.
I would take Plasma and hug a tree but thats just me.

"Though the blacks are a little deeper on my plasma, my LCD has better shadow detail. In other words, on dark scenes I see more detail on objects like buildings and the side of a person's face that is away from direct light."

Comparing the shaded areas between my XBR6 LCD and my Pioneer 151FD plasma the plasma is clearly better.

"This is also important and easily visible when you do a side by side comparison on the same material. As time goes on a plasma will grow dimmer(it will start to lose its brilliance).. an LCD doesn't."

Out of the box the XBR LCD was running at 8000 kelvin and the plasma was at 5750 kelvin. With both displays calibrated the plasma is clearly brighter. Modern plasmas now have a much longer lifespan than LCD.

"A plasma is more susceptible to burn in... LCDs are not."

Yes but modern plasmas now have firmware that greatly reduces the possibility of burn in.

Even with its high refresh rate my LCD has visible motion blur around object edges which by itself could be easily overlooked if it's you only display. During a high quality football broadcast the divots in the turf seem to be floating with the LCD.

Living with a modern plasma in the same house seems to magnify their differences to the point where I wouldn't recommend an LCD.