Seems a lot of people already have weighed in here, but I thought I'd add a little info...
There are a host of issues to look at, but cost is always a consideration. Size for size, res vs res, plasmas are still cheaper. Are they better? Well, that's a matter of debate. But here are some things I can tell you...
CRT's (conventional TV tubes), are very capable in a multitude of lighting situations. There is generally one specular and one diffuse surface. "Specular" meaning "mirror-like". So if there's a light source in the room, it will reflect an image of that source. Diffuse meaning just that, it reflects a fuzzed and/or reduced (or eliminated) source.
LCD's are GREAT in rooms with ambient light sources, there are generally NO specular surfaces in the display and the diffuse reflector surface is generally AR coated (meaning it will retartd or eliminate altoghther, reflections.).
Plasmas generally have not one, not two, but THREE specular reflecting surfaces. Which means that unless you're putting it in a home theater, with very well controlled lighting, you're GOING to get reflections and glare on the screen from light sources in the room. What does that mean? It's better in the dark...
Another thing, Plasmas tend to suffer the same problems that CRT's do with regards to high contrast images. Put a white square on a black background, and you get a very high contrast image. Lot's of manufactuters like to claim a 500:1 contrast ratio, and that's usually how they measure it. Now, reverse that and put a black square on a white background, and you start to deplete to white heavilly. In many cases, your contrast ratio could drop to as little as 40:1. LCD's don't suffer this effect to anywhere near the same degree, and can deliver more consistent images depending on lighting.
My preference? I wouldn't know, I couldn't afford either right now...
If anyone's interested, here's a really great spot to learn all you never wanted to know about flat panel displays...
http://www.fpdl.nist.gov/tips.htmlI just started doing some work in this project, and it's really cool. A nice change of pace from lasers and detectors and stuff...
-Josh2