If by "pixelated" you mean "burn-in" or "image retention" on your screen, there are some things you can try. I recommend contacting the manufacturer of your set to get their specific recommendation on how best to address the issue. If you meant the picture quality is grainy or fuzzy, either you have a poor quality video source or you may be sitting too close. Feel free to call for additional assistance: 800.315.0030--Crutchfield
While the latest generation of plasma displays are much less susceptible to burn-in, it is still a possibility. Feel free to call for additional assistance: 800.315.0030--Crutchfield
I have both (LCD in a room, Plasma in a basement). I can assert both are good but Plasma looks better for the reasons Steve (the speaker) said. Simply put, there is something slightly artificial looking about an LCD that one doesn't have with a Plasma.
Yet, it's a matter of comparing given that not all LCDs are the same (now there's also LED) and how much you care.