3. 'Half-Life'
Area 51, anyone? This first-person shooter game takes place at New Mexico's fictional Black Mesa Research Facility, where theoretical physicist Gordon Freeman is one of the only survivors of a botched experiment. In what will later be known as the Black Mesa Incident, a hole is ripped in the dimension, and a group of malevolent aliens step through. Gordon fights to escape the dangerous facility, but between staying alive and pleasing the government, it's no easy task.

It's certainly not the scariest game on the list, but for fans of conspiracy theories and aliens, it'll hit home.

Half-Life 2 continues the story as Gordon navigates the tarnished city the Black Mesa Incident leaves behind.