Hi Zeddy,
I'd place Samsung, Panasonic, and Sony in the top tier for image quality, whether plasma or LCD. LG is awfully close but not quite the equal of the top three, and Sharp is a distant third, partly because the loss of color and contrast of Sharp LCDs off-axis is much worse than other brands of LCD above and Sharp reliability is dubious.
Pioneer Kuro is an odd brand for me. Despite praise from some fellow journalists, the Pioneer Kuros at CES shows in Las Vegas always looked disappointing to my eyes, while other brands looked stunning.
Don't overlook Toshiba, whose flat screens are sometimes excellent and priced lower than others.
Also keep in mind that if you and others are going to be viewing the set from angles to the sides, plasma screens suffer no loss in image quality, unlike LCD viewed from an angle (Sharp being the worst). If you view LCD from mainly in front, then it doesn't matter.
Regards,
Alan
