From what I read so far:
Panasonic - better blacks, IPS panels, one year warranty (not sure if Home Service)
Samsung - warm and reddish in tint/color, panel lottery (you're not sure if IPS panel or lower quality), 2 years service (not sure if Home Service, but sure [based on posted complaints] that their warranty services suck
LG - some models suffered excessive backlight bleeding problems (not sure if corrected in 2011 models), 2 years warranty (sure that they do Home Service and their warranty services will treat you like a king)