Prior to returning to school in January, I was the sales manager for an audio video company back home for two years. 99% of our business was front projection systems (overhead projector and front screen) but we did our fair share of plasma/lcd installs and a few rear projection sets. Other than a front projection system, the absolute best bang for your buck right now is a rear projection LCD/DLP television. The colors are very crisp, picture detail and resolution is great, and the cost kicks flat panel TV's to the curb. The technology I hate the most is Plasma. Dark colors are not reproduced accurately, they put off a ton of heat, and I have had to send alot of plasmas in for service. With their picture quality, you have to spend usually in the $5-10,000 range to get an image as great as rear projections, or projectors for that matter. Now when I say rear projection, I am not talking about CRT. CRT is the type of big screen that we all grew up with in the 80's and 90's. While picture quality is usually very good (HDTV wise), the viewing angles suck, and they tend to be darker. They are also just very big size wise compared to newer technologies. I picked up a 44" Panasonic Rear Projection LCD Thanksgiving of last year on sale for $1200. It is a beautiful TV and has worked without a hitch. My original plan was to purchase a 42" or 50" Sony Rear projection LCD but I couldn't pass up the price on this one. Sony makes one of the best rear LCD's on the market and are worth looking at. Samsung also makes a beautiful rear DLP TV I would be happy to have.
Plasma, while not as popular due to larger LCD's, as it once was, is far from a dying technology. Several companies, such as Pioneer, only make a Plasma television and have devoted millions of dollars to R&D which will lead to cheaper and better versions down the road. Like I stated before, do not care for plasma at all but would prefer a large LCD to hang on my wall.
Flat Panel LCD's, while still very pricey for anything over a 32", are slowly coming down in price. Many versions are still at the price points that plasma was 3-5 years ago.