There are three basic components that determine the chewiness / crispness. First, it's a matter of the KIND of fat you use -- butter or margarine is not 100% fat, it contains water and dairy solids. So, these cookies spread more. If you use shortening, which IS 100% fat, there's no liquid or other substances so they come out chewier. Other factors include the gluten/protein content of the flour (less = crispier) and the amount of egg (less = crispier).
Check out this page: http://www.baking911.com/cookies_chocolate_chip.htm
She posts the Alton Brown 3-types-of-cookie recipes, as well as lots of other info. Basically, if you follow the recipe on the back of the Nestle Toll House chip bag as written, you'll get fairly crispy cookies.