when it comes to picture quality and color saturation, black levels plasma is superior and produce more natural picture, besides plasma has a wide viewing angle, no motion bluring in plasma, so the only 2 drawbacks are heat power consumption and burn in issue, if your going to go plasma make sure you get it full HD 1980x1080, 1080p. it won`t be easy to find but it would allow you to view full HD content in the future.
LED has better colors than normal flurencent LCD but LCD is cheaper.
Ya... i have chosen Panasonic plasma 50" XT series and smart viera but its HD READY. I have not bought yey