www.avsforum.com
browse the posts there. the forums are FILLED with people who have extensive experience with every variety of TV, whereas here you might find a couple people who have ~$3,000 TVs. (i have a Mitsubishi 48" RP-HDTV that is pretty badass, but people are paranoid about burn-in, so i won't recommend it. however, modern RPTV technology basically negates the potential for burn-in and has advantages over other technologies)
also, you can basically ignore the picture quality of the TVs on display at best buy. that isn't indicative of how the TV will look in your home. a big store has to split and amplify video signals to dozens and dozens of TVs, and each TV hardly gets a decent calibration that would show off its true potential.