Our local tech store guy uses his car windshield fluid mixed to a very dilute cocktail of about one part fluid to a dozen parts water. He uses it to clean all the screens in the shop and it seems to work quite well.
i use "iClean" from Monster. It works really good, sort of a gel spray stuff. You spray it on the included microfiber cloth and wipe the screen. Works great for removing dirt/oils from keyboards too.
I found the best thing for glossy screens to be simply water on a microfiber cloth. The cleaning products like iKlear all streaked on my screen making it pretty unusable until they went away which did not happen so quickly. I use iKlear on my matte MBP, both the screen and casing, and it works great.
I'm an advocate of iklear as well. When used properly, it makes my screen look as good as the day I got it, and also works for the casing, palmrests, keyboard, etc.
I've never been able to understand people who use iClear type stuff, polish, wipes or any other kind of cleaning agent on electronics gear - or anything else for that matter.
The ONLY thing to use is a damp lint free cloth. It's also the cheapest. This iClear stuff is just a con IMO