If you haven't ever tried chilling your dough, you need to. Chilling your dough leads to tastier and better looking cookies. They stay puffy, they cook more evenly, and the color actually looks better. Your cookies will taste better. The sugars have more time to absorb the moisture from other ingredients. This leads to a more condensed flavor, and sweeter tasting cookies. Less spreading. Thin cookies burn faster, but as the dough chills and hardens a little bit, they don't cook as flat. The chilling minimizes the spreading out of fat when you cook them. Everyone loves a thick chewy cookie with a soft middle. My mouth is watering just writing about these. A more appealing color. This again is related to the sugar in the cookie. Chilling the dough and sugar gives the cookie a more evenly golden color.