Plasma's are usually good, although when we were looking at TV's, the LCD's had better picture.
The listed contrast ratio means NOTHING.
Some TV's state its 1,000,000 to one, but when you look at the fine print closely, its really only 10,000 to 1 for "active" contrast ratio.
LG is pretty good, Sharp is arguably the best for the price.
Also, you need to realise, that unless you're watching a 1080i or 1080p movie (either with digital cable or blueray movie) that a REGULAR CRT or projection tv will appear better on normal cable channels.
Since the HD tv's are meant for HD, they cant adjust resolution like compulter monitors do, so they are scaling up the non digital image.
With plasma TV's you also gotta consider, that if you tilt it more than 30 degree's, the TV will be destroyed (due to the plasma screen)
I say LCD, they are more stable, and any 'problems' with burn in are gone with the new-er TV's. They have burn in protection which shifts the image 1 pixel every so often (which you cant see or notice at all) so it cant burn in.
ETA
We got a Vizio 47" LCD HDTV (which is basically uses all LG parts) and its got an incredible picture!
Watched a BluRay movie and it was amazing!