You need to look at two things: 1920x1080 Native resolution, and the ability to ACCEPT 1080p through HDMI. The first slew of '1080p' TVs had high enough resolution, but they could not accept 1080p through their inputs, so they would just scale 720p or 1080i up to 1080p.

a nice 40" FULL HD 1080p (1920x1200 resolution and accepts 1080p via HMDI) LCD would be the Sony 40" BRAVIA

 

I've heard good things about the Westinghouse 1080P monitors. I started out looking for their 47" model, but as of a few weeks ago none were to be had in the US. I thought about their 42", but fell in love with the picture on Mitsubishi's 52" 1080P DLP. The screen size is perfect as well, and it's dirt cheap (in a relative sort of way.) The only downsides - some hum from the color wheel and it's not LCD-thin.