The best cleaner that I have used for my Powerbook and Apple Cinema Display is found at your local Sunglass Hut.
Get a nice bottle of lens cleaner and, if you don't already own a pair of Oakleys, those nice semi-shiny cloths. In theory, I chose this as my cleaner because those lens cleaners must be gentle enough to clean a wide array of very very expensive lenses (polarized, Oakley plutonite, etc.) and can be used on a constant basis. The cloth is lint free, very soft and does a good job of not leaving any film behind.