I have a 2013 rMBP 15 and I'm looking for recommendations on cleaning the screen and body... Thanks.
I'm just guessing from the several responses that most of them don't wear glasses. I do, for 40-odd years. Don't use tap water - it's a poor "cleaner". Find a mirror or window, use a finger and tap on it as you would a keyboard for a bit, then use water and a microfiber cloth - you'll see smears and spots of mineral deposits (especially if you live in oil or natural gas country, where the water's hard). Those smears and splotches won't show up on your Mac, but they'll be there.
Most lenses in glasses are plastic or polycarbonate - the American Optometric Association recommends using ordinary dish soap with water (I use distilled water) and a microfiber cloth. I use a drop or two of unscented dish soap - the surfactant, which reduces the surface tension of water and oils - added to an ounce of distilled water in a sprayer bottle, along with a microfiber cloth.
I also use a high-powered mini vacuum to remove the crud from my keyboard that I picked up from Fry's for a few bucks.
Or, you can watch some slickly produced video with some guy that really doesn't know what he's talking about and buy into that...