Must be HD season... I've been looking at all this same stuff lately. I'm pretty sold on the Panasonic TH-42PZ700U 42" Plasma and at
$1335 it seems like a steal to me.
It hits all the points that are important to me, Plasma (the LCD "streaking" problem annoys me when fast motion is on the screen), 1080p, (i can usually see the diff. between 720p and 1080p, and 1080p looks so much cleaner) great contrast ratio and resolution and very dark black levels.
I've heard some good things about Vizio also, but the comments are usually from people who bought one as their first HD or LCD TV and have no comparison. Considering the Vizio that has similar specs to the Panasonic actually costs the same or even a little more, I'd rather have the Panasonic.