There are thousand of arguments for this topic. If you do a search at google.com, the return result is more then million pages. Below are comparisons of of the two technologies.

What the different of LCD and Plasma technology?
Plasma and LCD panels may look similar, but the flat screen and thin profile is where the similarities end. Plasma screens, uses a matrix of tiny gas plasma cells charged by precise electrical voltages to create picture. While LCD screens, as it name suggests, liquid crystal display are liquid crystal sandwiches between two glass panel. Again, electrical charge voltage applied to varying the liquid crystals. Plasma TV have slightly edge over LCD in term of black color display, which mean better contrast and detail in dark-colored movie scenes. The LCD technology, light source from CCFL (Cold Cathode Fluorescent Light) or white LED (latest version) shines through crystals panel and glasses layer, hard to achieve perfect black color because there is alway some light leakage in between pixels. Manufacturer keep improving with new technology and manufacturing advancement from generation to generation. Apart from better contrast with better ability to show perfect black, plasma screens do have wider viewing angles than LCD screens. Viewing angle mean how far you can sit on either side of screen before the image of screen disappear.

Samsung LED backlight Full HD LCD TV

For LCD screen, some brightness and color shift happen when viewing angle is high (far from center of screen). Plasma screen have better viewing angle compare to LCD screen. Manufacturer are improving the lagging of LCD screen technology to catch up with Plasma screen technology, and steadily changing with more and better LCD screen technology entering the market, where now the viewing angles of some model of LCD screen is equal or better then plasma screen. Plasma produce brighter color too, compare to LCD screen due to light leakage on LCD between pixels that affecting its color saturation.

Advantages of Plasma over LCD technology
LCD screens tend to has blur images in fast moving scenes in action movie or sport due to slow switching time of crystals from black to white. While this was true for older generation LCD screens, new models have improve significantly and close the gap between these two technology. The lowest the switching time for LCD, the better the image quality in fast moving scenes. Currently there is some manufacturer claim their LCD TV switching time as low as 2ms, while typically 6ms switching time will provide good fast moving scenes. Another advantage of Plasma is low price for screen size larger than or equal to 42-inch. This has changed recently where LCDs’ price for screen size of above 42-inch are matching or even beating plasma in both resolution and price.

Advantages of LCD over Plasma technology
Apart from being price competitive, LCD has the edge over plasma in several other key areas. LCDs tend to have higher native resolution than plasmas of similar size, in layman term, it mean more pixels on same area of screen. LCDs also consume less power than plasma screens with estimated power saving of more than 30 percents. Except for greener for LCD technology, it weight lighter than similar sized plasma TV and making it more feasible to mount on wall. The lifespan of LCD TV out-perform plasma TV where plasma screen would lose half of their brightness after more than 20,000 hours of viewing. While almost all LCD TVs have lifespan of 60,000 hours or more. However, newer version of plasmas have bumped up that lifespan to between 30,000 and 60,000 hours. Plasma TV prone to screen burn effect if static image left display on screen too long and resulting the ghost of image burned in permanently to plasma screen. Newer plasma TV less susceptible to this with improved technology. LCD screen do not suffer from this due to the picture is display via changing crystals.

LCD or plasma the mainstream technology in market today?
Currently only 3 manufacturer continue to roll out new models of Plasma TV, there are Panasonic, Pioneer and Hitachi. For LCD TV, there are tones of manufacturer and the price had drop more than 15 percents year-on-year. If you look for better resolution, go for LCD TV. If you prefer big screen size with good image quality, but not on resolution, Plasma is the right choice for you. Today LCD TV manufacturer drive full HD (High Definition) as the selling point to fight Plasma TV, but now new version of Plasma TV do support 1080p high resolution. Despite the current HD buzz, the content available in 1080p is still very little and you are paying the premium price of Full-HD for future, not tmorrow.