What is the safest cleaner to use on an lcd screen?

Don't use window cleaners. Window cleaners are for glass and LCD screens are covered by a film that can be damaged by ammonia, which is in Windex.

Use http://www.pixelclean.com/ - no ammonia or alcohol.

My LCD Users Manual says DO NOT use alcohol- or solvent-based cleaners on the screen.

I have to use only a dry, clean cloth (and avoid getting my fingers or anything else greasy on the screen). I remove any dust around once a week with an unused paint brush that has really soft fibres:))

But, refer to your own Users Manual or check the manufacturers website for your make and model.

I use plain water with a good 100% cotton tshirt, this works perfect. If it is that bad dillute a little windex in water. I have had to do that from time to time with no bad side effects. But it isn't recommended. I wouldn't recommend anything with alcohol in it specifically b/c it has properties that can dry out the screen on your lcd and eventually lead to cracking. Water is best.

Something cheap to get to is isopropyl-alcohol, cleans well and leaves no residue.

always try carefully that the plastic of the screen isn't sensitive to the alcohol as a solvent (I've never seen one, but can't hurt to be careful)

http://en.wikipedia.org/wiki/Isopropyl_alcohol

They sell these little whipes that are specifically for LCD monitors.

Alcohol based, pretty inexpesnive at any elctronics/office supply store

The method the mfgs manual tells you!

water