I use this:
http://www.chemicalguys.com/Window_C..._p/cld_677.htm

It's cost efficient compared to stoners and works great. Just make sure to have a quality glass towel. Also, remember to wash the MF before use. I bought a waffle weave glass towel that I though sucked, but then I gave it a wash and it works really well now. So invest in some good MFs and make sure to wash them in MF detergent before use to make sure they're clean and I guess it helps glass towels to be streak free