I've used the Meg's glass cleaner, Stoner IG, Clearvue, Sprayaway, just to name a few. I've use countless microfibers from both AG, Sam's club, all of the autoparts stores.
I've come to the conclusion that the wiping media matters more than the cleaner itself up to the point of severely tobacco stained windows in which I feel the cleaner will make a difference.
A few of you use something close to what I use in that you use newspaper. I use something similar, but not the newspaper. Though I've use newspaper a few times I came to the conclusion that if it turns my fingers black it's probably leaving something on the glass I can't see. That said, newspaper in my view is better than any microfiber I've used.
As far as cleaners, I'll use whatever I have on hand. Meg's happens to be cheap considering the cost and dilution ratio. However, when it comes to severely neglected glass, especially nicotine stained windows I switch gears altogther.
On nicotine stained windows I simply use the blue paper towels that you'd see at any gas station and 91% alcohol. I refuse to waste my time cleaning windows, but I hate filthy glass. Keep in mind I only use the alcohol if the job warrants it. Otherwise, I like to use those blue paper towels from the filling stations, even using water or washer fluid. I get the blue towels at a janitor supply house. Hint: There's a reason they are sold at janitor supply houses.