make sure it's not Pledge, or any other form of aerosol. I use that universal cleaning liquid that you can buy in computer shops, but as VoG™ syas - a soft cloth moistened with water and a tiny drop of liquid soap works perfectly.
I asked this same question to LG (I have a LG L1710B) and here is their response.
"Thank you for your e-mail and your purchase of an LG Electronics LCD TV. In order to clean the screen of the screen we would recommend only the use of a soft cotton lint free cloth lightly damped with plain water. The cloth should only be damp to the touch and not dripping. We would then recommend gently wiping the screen and rather than attempting to remove smears or finger prints in one attempt using repeated applications until the screen is clean and clear. Note: we do not recommend the use of monitor screen cleaners and would suggest that should you decide to use a monitor screen cleaner that you follow any instructions given carefully and use the cleaner sparingly unless otherwise advised"