Most people say to use either distilled water alone or distilled water with a very tiny amount of gentle detergent along with a clean, lintless, cotton towel. Do not use Windex or other types of glass cleaners which have ammonia in them that can ruin the coatings on the screen. I happen to like using a product supposedly made specifically for display screens called Endust Electronics. It is not the regular Endust dusting spray, but one specifically for this purpose. You spray it on a clean cotton towel, not directly on the TV. I have had excellent results with this with no evidence of damage to any of the displays I have used it on. It specifically states that there are no ammonia products or other chemicals which can harm the screen.