do a search, there's more than a few threads on flat panel tvs around here.
Best advice is do your own research and choose the unit that best suits your needs.
Best advice you can get is: look at the tvs and choose the one that suits your needs and gives you the image YOU like, not by name, not by type, just the one that looks good to you........for eg: at red flag deals I got into this nutbar who was harping on pioneer kuros. I went out and looked at them. Frankly, for twice the price of a similar item, I couldn't tell the difference.
Now I will say this: the new backlit LED and the OLEDs are fricking amazing. They are almost 3 dimensional. LED and OLED are what HD was to SD 4 yrs ago.......
Another word of advice? Go into the setup menus and set them all to normal. Stores are notorious for adjusting the sets to get the best image and compensate for shortcomings. Only problem is if the tv is dark, and you have to set the brightness way up, that will reduce the lifespan of the panel.
Oh, and don't be afraid of moving the TVs side by side. I did this recently with a 32" and the sales guy was in a panic, I simply told him: I want to see this tv on a true HD source. If you don't like it? TFB....lol...(you should have seen his face lol it was too funny).