I think LCD is taking over because they can do so much more with so much less. Plasma seems to have hit it's pinnacle and LCD is just getting better everyday. Right now I'd be hard pressed to tell the difference between a good LCD and a Plasma TV.
If you want a good tv, and you mentioned paying a high price for it, get an LCD with selective dimming technology. It has different names from different companies but in short it's when the back light is made of many small white leds and it has the ability to turn off ones in black sections of the screen. It's actually quite hard to find, but it's a nice touch. I keep my backlight almost off as modern LCDs are pretty bright on their own, but you don't have the contrast that you can get with a selective dimming model.
My TV is a cheapo LCD and I'm tickled pink with it. It's a 32 inch that only cost 300 dollars. It makes black by darkening the entire picture for dark scenes. That works surprisingly well actually as light scenes should naturally have lighter black, due to ambient lighting on the set. There are times when I can tell it's twitching back and forth, but mostly it's perfect.
Nun sacciu, nun vidi, nun ceru e si ceru durmiv.
I know nothing, I see nothing, I wasn't there,
and if I was there, I was asleep.