Plasma gives the better picture for 'Video' (Movies/TV etc), deeper blacks, less smearing on high speed motion, more natural looking colours.
Plasma's come in many resolutions, a common one being 1024x768, but high end plasmas can be as much as 1920x1080 now. But dont automatically be put off by a 1024x768 screen, viewed at the proper distance for their size, they look just amazing. The improved contrast and colour definition more than make up for the decreased resolution.
However....
If your a heavy gamer, then get an LCD. Plasma screens while being considerably improved over older models, can still be affected by plasma burn.
I use my PC for gaming, and have an LCD monitor.. But for movies I use a plasma TV. I've viewed LCD TV's and they just dont do it for me. Even the most expensive sets look smeary as soon as there is a camera pan, or fast action. I guess though that not all people notice it, as LCD TV's do seem to sell well.
Best really is goto a good shop, and look at the TV's for yourself. But remember in a lot of shops they will carefully setup the TV they want to sell, while the TV's they dont really care about will be set to look rubbish. If you are interested in a TV, ask them to set the contrast/brightness correctly, and ideally play a DVD/BluRay/HD-DVD on it
