Martha knows. She is a brilliant genius and has one of the most comprehensive, easily accessible websites in the world. I could go on all day, just go to her website! Also enjoy these bloopers from her shows, I was thinking of being Martha Stewart for Halloween (full disclosure: I am a nerd), and wanted to get into character.
The NY Times did their own comprehensive research about the "best" cookie, and have recommendations like leaving the dough to rest in the fridge for thirty-six hours!!
I hope the above links are helpful, and here's to good baking!