First thing you need to know is the contrast ratio is almost always over exaggerated because they list the dynamic contrast ratio which is only true if that "feature" is enabled. Though it's better to keep it off as it can cause more harm than good. Most LCD's have an actual contrast ratio of 1000:1 or lower. Plasma's generally have a much higher actual CR and deeper colors which provide an overall better picture.
Downside to plasma is they're heavier and consume the most power. Glare and screen burn-in are not much of a concern with today's plasma's AFAIK. Though if you're looking at Plasma's in a huge brightly lit box store the glare will probably be pretty bad which makes it difficult to make a decision.
Really the only specs you should be concerned with are the size, resolution, & inputs. Your eyes tell you the rest.