This is probably better for the technology and entertainment forum as there is already a thread on this topic.
First off, there is no bulb for Plasma... that is for DLP and other projection technologies.
I have had a Panasonic plasma for over a year. I game on it quite a bit(NCAA, HALO 3, Guitar Hero). No problems.
First off... Burn in is virtually non existent. It WAS a problem 10 years ago when they first came out. Unfortunately, the same outdated information still persists. It's pretty incredible some of the stories I've heard.
Occasionally you will get image retention if you leave something onscreen for an extended amount of time(black bars on a movie for example). HOWEVER, you won't notice it while you are playing a game or watching tv or a movie. the only time you would notice it is if you switched a video input that didn't have anything connected to it. For example, you select video input 3 on your tv and the screen is completely black because whatever you have connected to that input isn't on. That is the only time you'd notice it.
FINALLY, the image retention(which you can't see during normal viewing, anyway) goes away VERY QUICKLY. 5 minutes tops.
Burn in or image retention should not be a factor in your purchasing decision, IMO.
To further address your question, good plasmas(Panasonic, Samsung, Pioneer) have better contrast ratios than the better LCDs(Sony and Samsung). Contrast ratio is one of the most important parts of picture quality. Know this, though. Most of those contrast ratio numbers are fubar. There is no standardized way of measuring it so companies can fudge the numbers. With that being said, it is widely known by videophiles and proffesional sites that Plasma have a better contrast ratio.
If you want to PM me with your specific situation, I'd be more than happy help you out. I researched this for over a year and can list the pros and cons of both.
Also check out this thread:
http://www.operationsports.com/forum...ma-vs-lcd.html