What would be the best way to clean a LCDTV?

Do you mean clean the screen? If so I bought a gel type product at an electronics store. It is good for lcd and plasma. This particular brand is Phillips and the ingredients are: water, anionic tensid, sodium lauryl sulfat. Works very well.

Probably nothing chemical-based as this can erode the matte finish of your display. Also disregard any “TV screen cleaners” not primarily suited for lcd screens, that may be made to polish the glass tube of a more conventional set.
Your best bet, besides a commercial product, would be a very fine cloth and distilled water wiped in circular motion from the center of the screen to the margins. This fashion I noticed on the directions of a disposable cloth provided with an lcd screen purchase.