Well, Windex didn't work, now what?

This all basically boils down to personal preference. I absolutely swear by Eagle 1 20/20 Window Cleaner. Some other people also swear by Stoner's Glass Cleaner. It leaves a streak free shine, but takes a little longer to "rub-in" than other cleaners. People also use water and newspaper, or diapers. Windex works well, but I find it to be streaky somtimes. Also, do not use the no-name cleaners that claim to be "streak and cloud free", they aren't. At all.