Mad Catz's partnering with Activision to make Black Ops PrecisionAIM controllers for the next Call of Duty game, meaning these $50 wireless peripherals are probably the best way to experience things.
They look very similar to the official Xbox/PS3 controllers, but differ in that they have extra buttons on the back for extended control. There are two buttons, one on the back right and one on the back left, that you can program to mimic buttons or button combos on the front, so you don't need to move your thumb off of the stick if you want to melee, for example.
But, the best choice is probably to set it on Precision Aim mode, which slows down the thumbsticks so you can get a better sniping experience. Because this goes above and beyond the standard Xbox controller, and because it was developed in assistance with Activision, the people responsible for Call of Duty, it kinda makes it a necessity for people who are super serious at the game.
Mad Catz also has a Gunnar Optics ProGaming glasses pack, which comes with the Gunnar eyestrain-reducing glasses, but also a voice headset that clips right on the glasses themselves. This retails for $100.