Because you like SHODAN in System Shock
A resourceful ship systems engineer, Isaac Clarke does his best to batttle the infection spreading across space. See them in Dead Space.
They say they saved Adam Jensen by turning him into a cyborg, but he's not sure saved is the right word. See them in Deus Ex Series.
For Kazuya Mishima, the power of the Devil is now his and his alone. See them in Tekken .
Sarah Kerrigan is pretty much the Queen Bitch of the Universe. See them in StarCraft .
The only thing Albert Wesker cares about is turning himself into a God. See them in Resident Evil Series.
NiGHTS is a powerful but childlike spirit who hates being told what to do. See them in NiGHTS into Dreams.
He may be one of the Four Horsemen of the Apocalypse, but War still maintains a strong sense of honor. See them in Darksiders Series.
After being resurrected and discovering his new morphing abilities, Alex Mercer uses them to combat the virus now ravaging New York. See them in Prototype Series.
Red doesn't like to explain herself. She wants her work to do the talking. See them in Transistor.
A hardboiled 1940s detective, Cole Phelps is haunted by his past in World War II. See them in L.A. Noire.
Harry Mason has been told that he worries too much, that he's a little paranoid. But he just wants to protect what he loves. See them in Silent Hill.
A believer in the pursuit of justice, Garrus Vakarian hates it when bad guys slip through the cracks of the bureaucratic justice system. See them in Mass Effect.