In brief check
this thread.
But some LED TVs can have the same black levels as plasmas or performance in general.
If you want to use them with games then dont consider plasmas because they are suspected to burn-in though it may not fade in time.
Also dont ever believe the 600Hz subfield thingy because it is just for marketing and it doesn't logically exist for such prices, most 100/120 Hz(LCDs) may outperform 600Hz TVs in motion interpolation.
And at last one of the most important issue is its lifetime which because we Lebanese turn our TVs
on 24/7 so the color may become black and white after about 3 years, due to the consumption of the inert gas.