For details on specific tv models, I'd head over to
www.avsforum.com
I spent the most time on that site while I was researching.
As for a little guidance for which manufacturers to go with, I've read that consumers should stick with companies who manufacture their own LCD panels. From what I've read those companies are:
Sony/Samsung
LG/Philips
Sharp
Panasonic
Hitachi/Toshiba
Sony/Samsung (I think its actually a 3rd company who make the panels but they make them exclusively for these 2 companies)
As you can see, a number of those companies are actually teamed up. Like LG and Philips, and Hitachi and Toshiba. Those teamed up companies are using the same panel so its other components (processors, software, etc) which make the difference.
The reason people suggest sticking with manufacturers who make their own panels is something like this:
Company x manufactures an LCD panel and it goes through their testing and gets rated. A panel with a rating over, say, 90% is used for one of company x's tv sets. The other panels typically end up being sold.
Company y doesn't manufacture their own panels so they need to buy them somewhere. They end up buying company x's panels however they are most likely buying "grade B" panels. Thats why their TV's are cheaper (Vizio and Westinghouse for example).
Now, 2 points. This doesn't mean the "grade B" panels are crap. It just means it didn't meet what are likely to be very lofty standards. Because a company like Samsung is putting their name behind the product and since they have the means to make the panels, they have the ability to be very picky.
Point 2 is that companies like vizio and westinghouse don't necessary buy those grade B panels. They have the option of buying the "grade A's" but it would be at a higher cost. So if they are buying "grade A's" they would presumably cut corners somewhere else (ie software).
If you stick with one of the big manufacturers (ie anyone listed above) you probably can't go wrong. There may be small benefits or downfalls to each but you'll be happy with any of them. So compare the sets based on their other features and read the reviews. Also, make sure you compare like for like. Don't compare a 2006 Samsung to a late 2007 Toshiba. You'll likely have to dig a little to figure that info out (cnet reviews will likely help) but it will help you make a smarter decision.