Well the LG is cheaper by a $1k or more. You are getting two different 3D technologies. The new LG's have not been out long. So you may turn into a guinea pig. Or you may be an early adopter of the next best thing. Check out www.hdguru.com and search for 3D TV War Intensifies. He has a really good review between Active and Passive 3D technologies.
Really it all depends on why you are purchasing your TV? If 3D isn't necessary, then go with an LED that doesn't have it. If you may adopt it later. Research the different technologies.
Do you stream on-line content, Netflix, Hulu, etc? Then see which one does a better job. I looked into Samsung's abilities and their Apps were not ranked very highly.
Check out the manufacturer's website for each product. They spend massive amounts of money on marketing their products and telling you the features their TV's have. Like LG has a new 5 button Remote. It is Motion Activated like a Wii Remote! Sounds cool, but doesn't it work?
Check out BB and see the TVs for yourself if you can.
I own a Samsung LCD. Samsung was my first and second tv purchases. Mainly because of their customer service and because their picture qualities were awesome. My 1st was a 40" 720p and it rivaled some of the newer 1080p sets even today. However, my next tv will probably be a Vizio or an LG just because of the price margin. Samsung is the old Sony. You're now paying for the cool factor.