IMHO, the best way to go is Amazon. Think about this, you will save $20.00 on a future game purchase, and if you select game day delivery, you don't have to waste the gas or the energy to drive to some B&M, wait in line, deal with the other customers or (un)educated store staff.
In some instances, game day delivery is free for COD 4 MW 2. My buddy and I ordered it and we got free Game Day shipping somehow.