All down to personal preference. I love my plasma, feed it SD, or HD it scales it to its 'odd plasma' resolution (1024x768), and it always looks nice.
Naturally HD sources look best, but its still very good on SD.
To me LCD looks 'artificial' while plasma is more 'natural' looking. Panasonic's 10th generation plasma's are full 1920x1080 progressive, and are very impressive, but I'd rather have an old low res ED (854x480) plasma, than a full HD LCD for watching movies, and /or TV.
On the other hand, gaming LCD wins hands down due to the screenburn risk on plasmas.