I did a LOT of research befor ebuying my Panasonic Plasma and frankly I think the Pioneer and Sony's are overhyped. Even with the Kiro's blacker than black contrast ratios I wasn't impressed considering they were double the cost of everything else.
Which is THE best? As someone stated, it is all best bang for your buck and it is all determined by
resolution: 1080P or I, 720 etc
inputs: 1 2 or 3 HDMI
brightness, contrast, black to white to black refresh rates, ghosting, etc etc
My advice to anyone buying a Tlat Panel TV: go to a store ANY store, set ALL the tvs to neitral via the setup menu, and then review.
I think all but one brand come with a 1 yr warranty. I think Sammies come with a 2 but don't quote me on that.
But really, since there are only a few LCD and Plasma panel makers most have the same actual panels inside. It is only a matter of inputs and controlling electronics that make the difference....
(and to be honest, again, I found the Kiros to be WAY overhyped)