Part of the choice comes down to where the
HDTV is to be located. Is it in a bright room, or one without much natural light or too many lamps that will reflect light off the screen? Plasmas tend to do better in darker rooms because their glossier viewing-surface finish reflects daylight and lamp light.
LCD and LED-based sets are better in brighter rooms because their screens typically have matte finishes that diffuse reflected light.
LCD and LED refer to the type of backlight used rather than the display itself. The newer LED-based sets are noticeably brighter and more energy efficient than LCDs, which use fluorescent backlights. The energy savings of LEDs are significant: A recent
"road test" of the 46-inch Samsung LED-based
HDTV found it consumes 123 watts/hour with the backlight set at 5 on a scale of 10. That's roughly what a typical 26-inch
LCD set uses. With the backlight down at 1/10, energy use drops below 100 watts/hour. Significant energy savings like that can reduce power costs by $250 or more over the life of the set.
LED backlights also have much longer life than fluorescent-based
backlights -- maybe as much as 250,000 hours versus 50,000 hours or so.