Online through Amazon.
I don't have to waste the gas to go pick it up, every order I've made has qualified for free shipping, except release date delivery though it is only 99 cents for that, which is still cheaper than buying at a physical store, because physical store purchases usually have around 2 to 3 dollars of tax tacked on, while I've never been charged any tax on Amazon. So, I get things cheaper by using Amazon, and still get things on or the day before release.