Todd--
You have gotten some really good advice here. I think helenabear's might be the best.
One other thing to think about, is whether or not you want to get an HD ready set. The technology is coming, quicker than we all think, and it makes sense, to get the HD-ready, that way, when HD is mainstream, all you will need is the add on box, and you will be good to go.
The plasma burn-in issue is also being addressed, and will probably be fixed in the next couple or three years. It is still a VERY new technology, and with any such technology, there are 'issues' Same deal with LCD. Although, we have just gotten some devices in at work (not too familiar) that are kind of like a 'screen saver' for your plasma, which will help with the burn in problem.
The technology is growing by leaps and bounds, and it is going to be a very interesting next couple of years.
The only other advice I can give you, is to bring along a DVD or Video that you are VERY familiar with, and watch some of it on any TV you are thinking about, it will help you get a feel for the picture. A Sony is not a Panasonic, is not a Toshiba, is not a Mitusubishi, etc etc etc...
Good Luck, and have fun!!!
Debbie