Well to be honest with you Plasma does burn but, the LG's and the Samsungs have some good tech in them that corrects it and also Plasma gives you a more natural color and its a faster panel. Good Positive about Plasma is the bigger sizes are actually cheap.
But a really good investment would be to save up for a LED panel, its got the best of both worlds, the Durability of a LCD and the Color of a Plasma.