For gaming I have no idea, from a general viewing capacity my understanding was at the smaller end (below 42 inches) LCD was better and that for larger sizes Plamsa outperformed LCD for quality of image.
That said I haven't looked at this in 12 months so a lot could have changed either way.
There is a smaller chance of burn in on plasma than LCD, although I suspect you'd have to play a serious amount of the same game/HUD display to encounter it.
I tend to look for this info for image quality for film playback vs gaming as for me the number 1 issue is how good will my films look - I kind of assume that if the film looks good a game will too.
Try to be reasonable... its easier than you think...