try
www.trustedreviews.com
for some decent reviews of most current sets.
Plasma will tend to have the better picture quality, but they do eat electricity more than LCD.
LCD you can get half decent full HD sets for low money now, but for a decent full HD plasma it will cost you a little more. normal HD plasma are pretty cheap though.
LCD do still struggle with rainbow effect and motion blur, as well as black levels compared to plasma. To get a decent LCD that minimises these issues you will have to spend a bit more than average. Pretty much all LCD have a dynamic backlight now which can take some getting used to.