To add to Casey's comments--and I'd agree on his side-by-side judgment of LCD vs. plasma black levels--, the other advantage cited for LCD is that they're able to deliver a brighter picture than plasma in a brightly lit room.
However, all displays, when run in the so-called "torch mode" ( the setting often used by retail stores to demo TVs), result in burned out whites (no detail visible) because the pixels are over-driven, with color values that become over saturated and unrealistic. My own DLP run in this mode (Samsung calls it "Dynamic") is dazzlingly bright--ridulous, frankly, if you're looking for accurate color rendition.
Granted, there may be times when you have people over and you don't want to view the display in its "cinema" setting in a dim room, but it's better to use the middle setting rather than the brightest.
Regards,
Alan
