NaturalPoint TrackIR 4 Pro

Although not all games are compatible with its motion-sensitive capabilities, reviewers consider the NaturalPoint TrackIR 4 Pro (*Est. $100) a must-have for total game immersion and realism. The TrackIR is essentially two devices -- an infrared device that you connect to an earpiece or hat and a sensor you set above your television or monitor -- that together sense the movement of your head, allowing you to swivel, zoom, change views and perform a number of other functions through natural head motions. This capability frees up buttons on a gamer's other controllers for quickly swapping or reloading weapons or locking in on an enemy target. Most of all, it creates a newfound depth of game immersion. Reviewers also like how easy the TrackIR is to install and use.

The most in-depth review of the NaturalPoint TrackIR 4 Pro comes from FileFactory Games, which provides multiple pages of extremely detailed unpacking, installation and testing analysis. DriverHeaven.net and HubPages.com complement this review with generally glowing perspectives. Amazon.com does not have many reviews currently, but all are overwhelmingly positive.