What do you use to CLEAN audio equipment CASES?

Also a Sharpie Metallic (silver color) hides scratches on silver cased components. Just today got a Parasound tuner that had some bad scratches on top - the Metallic Sharpie covered them up a lot better than I expected.

Many thanks to everybody! This was all great information - just what I needed.

I've been using Meguiars All Purpose Cleaner diluted at a 1:10 ratio with water sprayed onto a microfibre to clean the case of a very dirty/dusty 2nd hand CD player that i recently purchased, by taking my time applying very little pressure in a circular motion alternating between the short pile and long pile sides of the microfibre towel and repeating the process several times it has broufht the unit back up to like new ...this technique i borrowed from times i spent detailing cars as the Megs APC is deemed safe on all surfaces in cars from fabric & leather to plastic, metal and wood  

1/2 distilled water, 1/2 91% isopropyl alcohol in a sprayer. This is also the absolute best car window cleaner. Dries fast, streak free.