As 'subdued ' says you do need to do some legwork and actually look at each model and compare technologies. I spent a wack of time looking and ended up with a 50inch LCD rear projection Hitachi . I have been more than pleased with it's performance to date ( about one year)You have to bear in mind that all the stores are showing dvd's or have hdtv hookup and all of the tv's look pretty good !!
I was not happy with the reported burnout of of plasma and wanted a reasonably big screen.The lamp can be replaced easily from the front ( when it becomes necessary !!
We do not have the hdtv box , just digital service,so quality of picture varies considerably depending how the content was shot, from awesome to mediocre! Just waiting to get Tivo or similar .
The most irritating aspect is the paucity of decent programming .The well worn ' 400 channels and nothing to watch ' syndrome .
We were laughing tonight about how many times they show 'Jaw's ' at least once a month !!
I'll stop rambling . Good luck with your search .........Dave
P.S. cnet has a lot of info and reviews from purchasers