I see this question a lot so I thought I would post this info I found, it helps to differentiate between the two;
Plasma vs LCD
The ADVANTAGES of Plasma over LCD are:
1. Larger screen size availability.
2. Better contrast ratio and ability to render deeper blacks.
3. Better color accuracy and saturation.
4. Better motion tracking (little or no motion lag in fast moving images).
The DISADVANTAGES of Plasma vs LCD include:
1. Plasma TVs are more susceptible to burn-in of static images.
2. Plasma TVs generate more heat than LCDs, due to the need to light of phosphors to create the images.
3. Does not perform as well at higher altitudes.
4. Shorter display life span (about 30,000 hours or 8 hrs of viewing a day for 9 years) than LCD. This can vary according to other environmental and use factors.
LCD television ADVANTAGES over Plasma include:
1. No burn-in of static images.
2. Cooler running temperature.
3. No high altitude use issues.
4. Increased image brightness over Plasma.
5. Longer display life (about 60,000 hours - at which time all you may need to do is replace the light source, not the entire set). This can vary according other environmental and use factors.
DISADVANTAGES of LCD vs Plasma televisions include:
1. Lower contrast ratio, not as good rendering deep blacks.
2. Not as good at tracking motion (fast moving objects may exhibit lag artifacts).
3. Not as available in large screen sizes above 37-inches
4. Although LCD televisions do not suffer from burn-in susceptibility, it is possible that individual pixels on an LCD televisions can burn out, causing small, visible, black or white dots to appear on the screen. Individual pixels cannot be repaired, the whole screen would need to be replaced at that point, if the individual pixel burnout becomes annoying to you.
5. LCD televisions are much more expensive than equivalent-sized Plasma televisions.
Hope this help someone