Get a projector instead, best bang for the buck. If your room is dark enough, go for a 3 chip LCD projector. If your room has some ambient light, get a single or 3 chip DLP projector.
As for Plasma vs LCD... I have noticed that good plasmas look better than good LCDs. The good plasmas seem to have better color, better viewing angle, more even lighting, darker blacks. BUT... to match the resolution of LCD, you have to spend a small fortune on a Plasma. LCD is far cheaper for midrange quality.
I prefer rear projection TVs. I like CRT based projection TVs the best, but they require a darker room and are very heavy, very large. Second best is a DLP projection TV, but my eyes can see the "rainbow" effect on single chip DLP projectors, which means I would need a 3 chip model, which gets expensive again.