Halo

In my opinion the coolest game series is "The Halo" series. For those of you that don't know, the Halo series is about a spartan who has the service tag number 117 but is widely known as master Chief. Here is the story so far. It is year 2552 and humanity has long been at war with the terrifying alien civilization that collectively calls its self the Covenant. This monstrous conglomerate of warlike species sees Humanity as a form of heresy against their religion- based in the single minded belief that a great Journey awaits its faithful and that this Journey can be embarked upon by firing an array of vast ring-like weapons scattered through out the galaxy.

What these rings, these Halos, do is destroy all sentient beings in the galaxy. The spartan-117-the Master Chief is the last fighting member of the legendary SPARTAN II military program and humanity's last best hope.