If you have a darken room, then plasma is hard to beat for picture quality. If your room is well lit or you have a light colored wall opposite the TV, then the black levels will be reduced due to reflection. My blog (www.highdefinitionblog.com
) has an entry describing this in detail.
If you have a brightly lit room and if you will have static elements such as window outlines present for any significant periods of time, the LCD may be best for you. I'd opt for a LCD that has a matte finish.
Personally I have both a plasma (Panasonic) and a LCD (LG) and I watch the LCD almost exclusively due to room lighting and connection to a HTPC.