I wouldn't say plasma or LCD is better they are different technologies to achieve the same end.
I have and LCD, but I would have preferred a plasma.
The reason I bought an LCD is because I live in Colorado, and plasma has a buzzing problem at altitude. While the plasma manufacturers have said they have fixed this problem on newer models, burned once twice shy.
Plasma is more power hungry then LCD, especially the new LED back-light LCD.
Plasma does burn in as well, just like the old CRT displays. LCD does not burn in but the older generation did have a image retention problem.
Plasma is less expensive to produce then LCD, but as the LCD technology began to compete with plasma, the plasma prices remained inflated but just below the price that the LCDs were being sold at. This kind of makes the plasma manufacturers look greedy.
all being all - I think the plasma picture is better due to the fact that it is more like the CRT that we all grew up with.