Had an LG 42" plasma for years then, when it went t*ts up a couple of years ago, I replaced it with a Sony LCD. The LG was a great picture, and still is, before the days of HD. I repaired it myself quite simply by replacing an internal board.
The Sony continues as a second TV for helimutt Jr. The LG is now my Study Room TV but have just bought a 50" Panasonic Viera, 1080 HD etc. I have to say, with Sky HD, the picture is fantastic. Exellent black reproduction. I'd buy the same again if I had to. If you can get what you want from John Lewis (online too) they give you that all important 5yr warranty. My earlier LG plasma died 1 month out of a 4 yr warranty. Power board was going to be £480 to replace it. Did it myself in the end with an ebay bargain TV I stripped.
LG make the majority of components for Plasmas, ie sony etc, they just add the audio/video boards to give their own characteristics.
LG are great TV's
Sony are good but I don't like the connectivity of them.
Panasonic is best i've seen out of the Samsungs etc i compared.
Go plasma every time.
In a test, over 60% of viewers of two tv's , plasma and LCD, chose the plasma picture as the better of the two. All down to personal choice I suppose.